{"id":1611,"date":"2026-07-15T17:58:38","date_gmt":"2026-07-15T08:58:38","guid":{"rendered":"https:\/\/www.nibb.ac.jp\/plantdic\/blog\/?p=1611"},"modified":"2026-07-15T17:58:38","modified_gmt":"2026-07-15T08:58:38","slug":"%e3%82%ab%e3%83%8a%e3%83%9c%e3%82%a6%e3%83%8e%e3%82%ad%e7%a7%91-didiereaceae","status":"publish","type":"post","link":"http:\/\/www.nibb.ac.jp\/plantdic\/blog\/?p=1611","title":{"rendered":"\u30ab\u30ca\u30dc\u30a6\u30ce\u30ad\u79d1 Didiereaceae"},"content":{"rendered":"\n
\"\"<\/a><\/figure>\n\n\n\n

\u30ab\u30ca\u30dc\u30a6\u30ce\u30ad\u79d1  Didiereaceae \u306f\u3001\u4e7e\u71e5\u5730\u306b\u9069\u5fdc\u3057\u305f\u591a\u8089\u6027\u6728\u672c\u690d\u7269\u304b\u3089\u306a\u308b\u3002\u5199\u771f\u306f\u3001\u30de\u30c0\u30ac\u30b9\u30ab\u30eb\u5357\u90e8\u306e\u6709\u523a\u4f4e\u6728\u6797\u3092\u4ee3\u8868\u3059\u308bAlluaudia<\/em> <\/em>procera<\/em>\u3067\u3042\u308b\u3002<\/p>\n\n\n\n

The family Didiereaceae consists of succulent woody plants adapted to arid environments. The photograph shows Alluaudia procera<\/em>, a representative species of the spiny bush forests of southern Madagascar.<\/p>\n\n\n\n

\"\"<\/a><\/figure>\n\n\n\n

\u30ab\u30ca\u30dc\u30a6\u30ce\u30ad Didierea madagascariensis <\/em>\u3067\u306f\u3001\u8089\u8cea\u8449\u304c\u843d\u3061\u308b\u3068\u92ed\u304f\u5f37\u976d\u306a\u523a\u3060\u3051\u304c\u6b8b\u308b\u3002\u5012\u308c\u308b\u3068\u6bb5\u30dc\u30fc\u30eb\u3084\u7d68\u6bef\u3092\u8cab\u901a\u3059\u308b\u3053\u3068\u3082\u3042\u308b\u305f\u3081\u3001\u53d6\u308a\u6271\u3044\u306b\u306f\u6ce8\u610f\u304c\u5fc5\u8981\u3067\u3042\u308b\u3002<\/p>\n\n\n\n

In Didierea madagascariensis<\/em>, when the succulent leaves fall, only the sharp, robust spines remain. If the plant falls over, the spines may even pierce cardboard or carpets, so it must be handled with care.<\/p>\n\n\n\n

\"\"<\/a>
\u30ab\u30ca\u30dc\u30a6\u30ce\u30ad\u79d1\u5404\u5c5e\u306e\u7a2e\u6570\u3068\u5206\u5e03 Species number and distribution of genera in Didiereaceae<\/strong>
Source: POWO (2026). Plants of the World Online<\/em>. Facilitated by the Royal Botanic Gardens, Kew. Published on the Internet; https:\/\/powo.science.kew.org\/<\/a>. Retrieved 7 July 2026. Distribution data from Kew Backbone Distributions (WCVP). \u00a9 World Checklist of Vascular Plants, licensed under CC BY 3.0.<\/figcaption><\/figure>\n\n\n\n

\u30ab\u30ca\u30dc\u30a6\u30ce\u30ad<\/strong>\u79d1\u5404\u5c5e\u306e<\/strong>\u7a2e\u6570\u3068<\/strong>\u5206\u5e03<\/strong> <\/strong> Species number and distribution of genera in Didiereaceae<\/strong><\/p>\n\n\n\n

\u30ab\u30ca\u30dc\u30a6\u30ce\u30ad\u79d1 Didiereaceae \u306f\u3001\u30dd\u30fc\u30c1\u30e5\u30e9\u30ab\u30ea\u30a2\u5c5e Portulacaria <\/em>(7\u7a2e)\u3001\u30ab\u30ea\u30d7\u30c8\u30ed\u30c6\u30ab\u5c5e Calyptrotheca <\/em>(2\u7a2e)\u3001\u30a2\u30e9\u30a6\u30c7\u30a3\u30aa\u30d7\u30b7\u30b9\u5c5e Alluaudiopsis <\/em>(2\u7a2e)\u3001\u30c7\u30ab\u30ea\u30a2\u5c5e Decarya <\/em>(1\u7a2e)\u3001\u30ab\u30ca\u30dc\u30a6\u30ce\u30ad\u5c5e Didierea <\/em>(2\u7a2e)\u3001\u30a2\u30e9\u30a6\u30c7\u30a3\u30a2\u5c5e Alluaudia <\/em>(6\u7a2e)\u306e6\u5c5e\u304c\u77e5\u3089\u308c\u3066\u3044\u308b\uff08POWO)\u3002 <\/p>\n\n\n\n

The family Didiereaceae comprises six known genera: Portulacaria<\/em> (7 species), Calyptrotheca<\/em> (2 species), Alluaudiopsis<\/em> (2 species), Decarya<\/em> (1 species), Didierea<\/em> (2 species), and Alluaudia<\/em> (6 species) (POWO).<\/p>\n\n\n\n

\"\"<\/a>
\u30ab\u30ca\u30dc\u30a6\u30ce\u30ad\u79d1\u306e\u5c5e\u306e\u7cfb\u7d71\u95a2\u4fc2 Phylogeny of Didiereaceae genera<\/strong><\/figcaption><\/figure>\n\n\n\n

\u30ab\u30ca\u30dc\u30a6\u30ce\u30ad\u79d1\u306e\u5c5e\u306e\u7cfb\u7d71\u95a2\u4fc2<\/strong> <\/strong>Phylogeny of Didiereaceae genera<\/strong><\/p>\n\n\n\n

\u30ab\u30ca\u30dc\u30a6\u30ce\u30ad\u79d1 Didiereaceae \u306f\u3001\u5206\u5b50\u7cfb\u7d71\u89e3\u6790\u306b\u57fa\u3065\u304d\u3001\u30a2\u30f3\u30b4\u30e9\u304b\u3089\u5357\u30a2\u30d5\u30ea\u30ab\u306b\u5206\u5e03\u3059\u308b\u30dd\u30fc\u30c1\u30e5\u30e9\u30ab\u30ea\u30a2\u4e9c\u79d1 Portulacarioideae\u3001\u6771\u30a2\u30d5\u30ea\u30ab\u306b\u5206\u5e03\u3059\u308b\u30ab\u30ea\u30d7\u30c8\u30ed\u30c6\u30ab\u4e9c\u79d1 Calyptrothecoideae\u3001\u304a\u3088\u3073\u30de\u30c0\u30ac\u30b9\u30ab\u30eb\u306b\u5206\u5e03\u3059\u308b\u30ab\u30ca\u30dc\u30a6\u30ce\u30ad\u4e9c\u79d1 Didiereoideae \u306e3\u4e9c\u79d1\u306b\u5206\u304b\u308c\u308b\u3068\u63a8\u5b9a\u3055\u308c\u3066\u3044\u308b\uff08Bruyns et al. 2014\uff09\u3002<\/p>\n\n\n\n

\u30ab\u30ca\u30dc\u30a6\u30ce\u30ad\u79d1\u306f\u3001\u53e4\u7b2c\u4e09\u7d00\u6681\u65b0\u4e16\u306e\u7d045,900\u4e07\u5e74\u524d\u306b\u59c9\u59b9\u7fa4\u304b\u3089\u5206\u5c90\u3057\u305f\u3068\u63a8\u5b9a\u3055\u308c\u3066\u3044\u308b (Zuntini et al. 2024)\u3002\u307e\u305f\u3001\u30dd\u30fc\u30c1\u30e5\u30e9\u30ab\u30ea\u30a2\u5c5e Portulacaria<\/em>\u3001\u30ab\u30ea\u30d7\u30c8\u30ed\u30c6\u30ab\u5c5e Calyptrotheca<\/em> <\/em>\u304c\u30a2\u30d5\u30ea\u30ab\u5927\u9678\u306b\u5206\u5e03\u3059\u308b\u3053\u3068\u3001\u3055\u3089\u306b\u30de\u30c0\u30ac\u30b9\u30ab\u30eb\u304c\u7d041\u51042\u5343\u4e07\u5e74\u524d\u306b\u306f\u3059\u3067\u306b\u30a2\u30d5\u30ea\u30ab\u5927\u9678\u6c96\u306e\u73fe\u5728\u306e\u4f4d\u7f6e\u306b\u3042\u3063\u305f\u3053\u3068\u304b\u3089\u3001\u30ab\u30ca\u30dc\u30a6\u30ce\u30ad\u4e9c\u79d1 Didiereoideae \u306f\u3001\u30a2\u30d5\u30ea\u30ab\u5927\u9678\u306b\u5206\u5e03\u3057\u3066\u3044\u305f\u7956\u5148\u304c\u9577\u8ddd\u96e2\u5206\u6563\u306b\u3088\u3063\u3066\u30de\u30c0\u30ac\u30b9\u30ab\u30eb\u3078\u5230\u9054\u3057\u3001\u305d\u3053\u3067\u591a\u69d8\u5316\u3057\u305f\u53ef\u80fd\u6027\u304c\u9ad8\u3044 (Bruyns 2014)\u3002<\/p>\n\n\n\n

Based on molecular phylogenetic analyses, the family Didiereaceae is inferred to comprise three subfamilies: Portulacarioideae, distributed from Angola to South Africa; Calyptrothecoideae, distributed in East Africa; and Didiereoideae, distributed in Madagascar (Bruyns et al. 2014).<\/p>\n\n\n\n

The family Didiereaceae is estimated to have diverged from its sister group approximately 59 million years ago, in the Paleocene of the Paleogene (Zuntini et al. 2024). In addition, because Portulacaria<\/em> and Calyptrotheca<\/em> occur on the African continent, and because Madagascar had already reached its present position off the coast of Africa by approximately 120 million years ago, the subfamily Didiereoideae most likely originated from an African ancestor that reached Madagascar by long-distance dispersal and subsequently diversified there (Bruyns et al. 2014).<\/p>\n\n\n\n

\"\"<\/a>
\u30dd\u30fc\u30c1\u30e5\u30e9\u30ab\u30ea\u30a2\u4e9c\u79d1\u00a0 Portulacarioideae<\/strong><\/figcaption><\/figure>\n\n\n\n

\u30dd\u30fc\u30c1\u30e5\u30e9\u30ab\u30ea\u30a2\u4e9c\u79d1<\/strong>  <\/strong>Portulacarioideae<\/strong><\/p>\n\n\n\n

\u30dd\u30fc\u30c1\u30e5\u30e9\u30ab\u30ea\u30a2\u4e9c\u79d1 Portulacarioideae \u306f\u30dd\u30fc\u30c1\u30e5\u30e9\u30ab\u30ea\u30a2\u5c5e Portulacaria <\/em>\u306e\u307f\u3092\u542b\u3080\u3002 <\/p>\n\n\n\n

Portulacarioideae contains only the genus Portulacaria<\/em>.<\/p>\n\n\n\n

\"\"<\/a>
\u30dd\u30fc\u30c1\u30e5\u30e9\u30ab\u30ea\u30a2\u5c5e \u2013 1. \u8349\u59ff\u00a0 Portulacaria <\/em>\u2013 1: Habit<\/strong>
Portulacaria afra<\/em>_1: cropped a photo by Adriaan Grobler, https:\/\/www.inaturalist.org\/photos\/346660774, CC BY-NC<\/figcaption><\/figure>\n\n\n\n

\u30dd\u30fc\u30c1\u30e5\u30e9\u30ab\u30ea\u30a2\u5c5e<\/strong> \u2013 1. <\/strong>\u8349\u59ff<\/strong>  <\/strong>Portulacaria <\/em><\/strong>\u2013 1: Habit<\/strong><\/p>\n\n\n\n

\u30dd\u30fc\u30c1\u30e5\u30e9\u30ab\u30ea\u30a2\u5c5e Portulacaria<\/em> \u306f\u3001\u30a2\u30f3\u30b4\u30e9\u304b\u3089\u5357\u30a2\u30d5\u30ea\u30ab\u306b\u304b\u3051\u3066\u81ea\u751f\u3059\u308b7\u7a2e\u304b\u3089\u306a\u308b\uff08POWO\uff09\u3002\u704c\u6728\u307e\u305f\u306f\u4f4e\u6728\u3067\u3001\u5927\u304d\u304f\u306a\u308b\u3068\u9ad8\u3055\u6570\u30e1\u30fc\u30c8\u30eb\u306b\u9054\u3059\u308b\uff08Carolin 1993\uff09\u3002<\/p>\n\n\n\n

The genus Portulacaria<\/em> comprises seven species native from Angola to South Africa (POWO). They are bushy or shrubby plants, reaching several meters in height when large (Carolin 1993).<\/p>\n\n\n\n

\"\"<\/a>
\u30dd\u30fc\u30c1\u30e5\u30e9\u30ab\u30ea\u30a2\u5c5e \u2013 2. \u830e\u8449\u00a0 Portulacaria <\/em>\u2013 2. Stems and leaves<\/strong><\/figcaption><\/figure>\n\n\n\n

\u30dd\u30fc\u30c1\u30e5\u30e9\u30ab\u30ea\u30a2\u5c5e<\/strong> \u2013 2. <\/strong>\u830e\u8449<\/strong>  <\/strong>Portulacaria <\/em><\/strong>\u2013 2. Stems and leaves<\/strong><\/p>\n\n\n\n

\u830e\u3068\u8449\u306f\u8089\u8cea\u3067\u3042\u308b\u3002 <\/p>\n\n\n\n

The stems and leaves are succulent.<\/p>\n\n\n\n

\"\"<\/a>
\u30dd\u30fc\u30c1\u30e5\u30e9\u30ab\u30ea\u30a2\u5c5e \u2013 3. \u82b1\u5e8f\u3068\u82b1\u00a0 Portulacaria <\/em>\u2013 3. Inflorescences and Flowers<\/strong>
Portulacaria namaquensis<\/em>_1: cropped from a photo by Karel du Toit (+2782 4928291) , https:\/\/www.inaturalist.org\/photos\/398950896, CC BY-NC
Portulacaria fruticulose<\/em>_1: cropped from a photo by Karel du Toit (+2782 4928291) , https:\/\/www.inaturalist.org\/photos\/644204588, CC BY-NC
Marloth, R. (1913). The Flora of South Africa, Volume I (Darter Bros. & Co.).<\/figcaption><\/figure>\n\n\n\n
\"\"<\/a>
Portulacaria afra<\/em>_2: cropped a photo by Saplants, https:\/\/commons.wikimedia.org\/wiki\/File-Portulacaria_afra_1DS-II_2-5243.jpg, CC BY-SA 4.0<\/figcaption><\/figure>\n\n\n\n

\u30dd\u30fc\u30c1\u30e5\u30e9\u30ab\u30ea\u30a2\u5c5e<\/strong> \u2013 3. <\/strong>\u82b1\u5e8f\u3068\u82b1<\/strong>  <\/strong>Portulacaria <\/em><\/strong>\u2013 3. Inflorescences and Flowers<\/strong><\/p>\n\n\n\n

\u30ac\u30af\u7247\u306f\u5bfe\u751f\u3059\u308b2\u679a\u304b\u3089\u306a\u308a\u30015\u679a\u306e\u82b1\u5f01\u306f1\u8f2a\u3092\u306a\u3057\u3066\u5f62\u6210\u3055\u308c\u308b\u3002\u96c4\u305a\u3044\u306f\u901a\u5e385\u672c\u3067\u3001\u82b1\u5f01\u3068\u4e92\u751f\u3059\u308b\uff08Erbar and Leins 2006\uff09\u3002\u82b1\u306f\u4e21\u6027\u82b1\u307e\u305f\u306f\u5358\u6027\u82b1\u3067\u3042\u308b\uff08Carolin 1993\uff09\u3002\u6700\u5916\u5074\u306e2\u679a\u306e\u82b1\u5668\u5b98\u304c\u82de\u8449\u3067\u3042\u308b\u304b\u30ac\u30af\u7247\u3067\u3042\u308b\u304b\u306b\u3064\u3044\u3066\u306f\u8b70\u8ad6\u304c\u3042\u308b\uff08Carolin 1993\uff09\u3002\u30ab\u30ca\u30dc\u30a6\u30ce\u30ad\u4e9c\u79d1 Didiereoideae \u3067\u306f\u82b1\u88ab\u304c2\u8f2a\u304b\u3089\u306a\u308b\u305f\u3081\u3001\u6700\u5916\u5074\u306e2\u679a\u306e\u82b1\u5668\u5b98\u306f\u82de\u8449\u3068\u89e3\u91c8\u3055\u308c\u3066\u3044\u308b\uff08e.g. Kubitzki 1993\uff09\u3002\u4e00\u65b9\u3001Portulacaria<\/em> \u3067\u306f\u82b1\u88ab\u304c1\u8f2a\u3067\u3042\u308b\u305f\u3081\u3001\u6700\u5916\u5074\u306e2\u679a\u306e\u82b1\u5668\u5b98\u304c\u30ac\u30af\u7247\u3068\u82de\u8449\u306e\u3069\u3061\u3089\u306b\u76f8\u540c\u3067\u3042\u308b\u304b\u3092\u5224\u65ad\u3059\u308b\u3053\u3068\u306f\u96e3\u3057\u3044\u3002\u3057\u304b\u3057\u3001\u3053\u3053\u3067\u306f Didiereaceae \u306e\u4ed6\u306e\u5c5e\u306b\u304a\u3051\u308b\u82de\u8449\u3068\u5f62\u614b\u304c\u985e\u4f3c\u3057\u3066\u3044\u308b\u3053\u3068\u304b\u3089\u3001\u82de\u8449\u3068\u3057\u3066\u6271\u3046\u3002<\/p>\n\n\n\n

\u5358\u6027\u82b1\u3092\u5f62\u6210\u3059\u308b\u7a2e\u306f\u3001\u304b\u3064\u3066 Ceraria<\/em> \u5c5e\u3068\u3057\u3066\u533a\u5225\u3055\u308c\u3066\u3044\u305f\u304c\uff08Pearson and Stephens 1912\uff09\u3001\u5206\u5b50\u7cfb\u7d71\u89e3\u6790\u306b\u3088\u308a Portulacaria<\/em> \u306b\u542b\u307e\u308c\u308b\u3053\u3068\u304c\u793a\u3055\u308c\u305f\uff08Bruyns et al. 2014\uff09\u3002<\/p>\n\n\n\n

The sepals consist of two opposite organs, and the five petals are formed in a single whorl. The stamens are usually five in number and alternate with the petals (Erbar and Leins 2006). The flowers are bisexual or unisexual (Carolin 1993). Whether the two outermost floral organs are bracts or sepals has been debated (Carolin 1993). In the subfamily Didiereoideae, the perianth consists of two whorls, and therefore the two outermost floral organs are interpreted as bracts (e.g. Kubitzki 1993). In Portulacaria<\/em>, by contrast, the perianth consists of a single whorl, making it difficult to determine whether the two outermost floral organs are homologous to sepals or bracts. Here, however, they are treated as bracts because they are morphologically similar to the bracts in other genera of Didiereaceae.<\/p>\n\n\n\n

Species with unisexual flowers were formerly segregated as the genus Ceraria<\/em> (Pearson and Stephens 1912), but molecular phylogenetic analyses have shown that they are nested within Portulacaria<\/em> (Bruyns et al. 2014).<\/p>\n\n\n\n

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\u30dd\u30fc\u30c1\u30e5\u30e9\u30ab\u30ea\u30a2\u5c5e \u2013 4. \u679c\u5b9f\u00a0 Portulacaria <\/em>\u2013 4. Fruits<\/strong>
Portulacaria afra<\/em>_3: cropped from a photo by Abdul-lateef Ismail, https:\/\/www.inaturalist.org\/photos\/246678573, CC BY-NC
Portulacaria afra<\/em>_4: cropped from a photo by Sharon Louw, https:\/\/www.inaturalist.org\/photos\/352168141, CC BY-NC<\/figcaption><\/figure>\n\n\n\n

\u30dd\u30fc\u30c1\u30e5\u30e9\u30ab\u30ea\u30a2\u5c5e<\/strong> \u2013 4. <\/strong>\u679c\u5b9f<\/strong>  <\/strong>Portulacaria <\/em><\/strong>\u2013 4. Fruits<\/strong><\/p>\n\n\n\n

\u679c\u5b9f\u306f\u8584\u58c1\u306e\u5805\u679c\u3067\u3042\u308b\u3002<\/p>\n\n\n\n

The fruit is a thin-walled nut.<\/p>\n\n\n\n

\"\"<\/a>
\u30ab\u30ea\u30d7\u30c8\u30ed\u30c6\u30ab\u4e9c\u79d1\u00a0 Calyptrothecoideae<\/strong><\/figcaption><\/figure>\n\n\n\n

\u30ab\u30ea\u30d7\u30c8\u30ed\u30c6\u30ab<\/strong>\u4e9c\u79d1<\/strong>  <\/strong>Calyptrothecoideae<\/strong><\/p>\n\n\n\n

\u30ab\u30ea\u30d7\u30c8\u30ed\u30c6\u30ab\u4e9c\u79d1 Calyptrothecoideae \u306f\u3001\u30ab\u30ea\u30d7\u30c8\u30ed\u30c6\u30ab\u5c5e\u306e\u307f\u3092\u542b\u307f\u3001\u591a\u6570\u306e\u96c4\u305a\u3044\u3092\u3082\u3064\u3053\u3068\u3001\u304a\u3088\u3073\u84cb\u72b6\u306b\u958b\u304f\u679c\u5b9f\u3092\u3064\u3051\u308b\u3053\u3068\u3092\u7279\u5fb4\u3068\u3059\u308b\u3002<\/p>\n\n\n\n

The genus Calyptrotheca<\/em> is characterized by having numerous stamens and fruits that open by a lid-like cap.<\/p>\n\n\n\n

\"\"<\/a>
\u30ab\u30ea\u30d7\u30c8\u30ed\u30c6\u30ab\u5c5e -1. \u8349\u59ff\u3068\u8449\u00a0 Calyptrotheca<\/em> -1. Habit and Leaves<\/strong>
Calyptrotheca taitensis<\/em>-1: cropped a photo by nsheldrick, https:\/\/www.inaturalist.org\/photos\/616932934, CC BY-NC
Calyptrotheca taitensis<\/em>-2: cropped a photo by nsheldrick, https:\/\/www.inaturalist.org\/photos\/616932923, CC BY-NC
Calyptrotheca taitensis<\/em>-3: cropped a photo by nsheldrick, https:\/\/www.inaturalist.org\/photos\/616932905, CC BY-NC<\/figcaption><\/figure>\n\n\n\n

\u30ab\u30ea\u30d7\u30c8\u30ed\u30c6\u30ab\u5c5e<\/strong> -1. <\/strong>\u8349\u59ff<\/strong>\u3068\u8449<\/strong>  <\/strong>Calyptrotheca<\/em><\/strong> -1. Habit and Leaves<\/strong><\/p>\n\n\n\n

\u30ab\u30ea\u30d7\u30c8\u30ed\u30c6\u30ab\u5c5e Calyptrotheca<\/em> \u306f\u3001\u30a2\u30d5\u30ea\u30ab\u6771\u90e8\u306b\u5206\u5e03\u3059\u308b2\u7a2e\u304b\u3089\u306a\u308b (POWO)\u3002\u4f4e\u6728\u307e\u305f\u306f\u5c0f\u9ad8\u6728\u3067\u3001\u9ad8\u30557 m\u306b\u9054\u3059\u308b\u3002\u8449\u306f\u3084\u3084\u591a\u8089\u8cea\u3067\u3001\u7e01\u306f\u3084\u3084\u6ce2\u6253\u3064 (Carolin 1993 )\u3002 <\/p>\n\n\n\n

The genus Calyptrotheca<\/em> comprises two species distributed in East Africa (POWO). They are shrubs or small trees reaching up to 7 m in height. The leaves are somewhat succulent, with slightly undulate margins (Carolin 1993).<\/p>\n\n\n\n

\"\"<\/a>
\u30ab\u30ea\u30d7\u30c8\u30ed\u30c6\u30ab\u5c5e -2. \u82b1\u5e8f\u3068\u82b1\u00a0 Calyptrotheca<\/em> \u2013 2. Inflorescences and Flowers<\/strong>
Modified from Pax, F. and Hoffmann, K. (1936), Die nat\u00fcrlichen Pflanzenfamilien<\/em>, 2nd ed., Bd. 17b: 207. Public domain, via Biodiversity Heritage Library.
Calyptrotheca taitensis<\/em>-3: cropped a photo by nsheldrick, https:\/\/www.inaturalist.org\/photos\/616932905, CC BY-NC<\/figcaption><\/figure>\n\n\n\n

\u30ab\u30ea\u30d7\u30c8\u30ed\u30c6\u30ab\u5c5e<\/strong> -2. <\/strong>\u82b1\u5e8f\u3068\u82b1<\/strong>  <\/strong>Calyptrotheca<\/em><\/strong> \u2013 2. Inflorescences and Flowers<\/strong><\/p>\n\n\n\n

\u30ab\u30ea\u30d7\u30c8\u30ed\u30c6\u30ab\u5c5e Calyptrotheca<\/em> \u306e\u82b1\u306f\u30012\u679a\u306e\u30ac\u30af\u7247\u30685\u679a\u306e\u82b1\u5f01\u304b\u3089\u306a\u308b\u3002\u305f\u3060\u3057\u3001\u6700\u5916\u5074\u306e2\u679a\u306e\u82b1\u5668\u5b98\u3092\u82de\u8449\u3068\u89e3\u91c8\u3059\u308b\u304b\u3001\u30ac\u30af\u7247\u3068\u89e3\u91c8\u3059\u308b\u304b\u306b\u3064\u3044\u3066\u306f\u3001Portulacaria<\/em> \u306e\u5834\u5408\u3068\u540c\u69d8\u306b\u3001\u660e\u78ba\u3067\u306f\u306a\u3044\u3002\u96c4\u305a\u3044\u306f60\u672c\u307b\u3069\u306b\u3082\u306a\u308a\u30011\u672c\u306e\u82b1\u67f1\u304c\u9577\u304f\u4f38\u3073\u51fa\u3059\u305f\u3081\u3001\u30d5\u30a6\u30c1\u30e7\u30a6\u30bd\u30a6\u79d1 Capparaceae \u306e\u82b1\u306b\u4f3c\u3066\u3044\u308b\u3002\u3053\u306e\u5c5e\u306f\u3001\u300c\u84cb\u306e\u3042\u308b\u5bb9\u5668\u300d\u3092\u610f\u5473\u3059\u308b\u5c5e\u540d\u304c\u793a\u3059\u3088\u3046\u306b\u3001\u84b4\u679c\u304c\u57fa\u90e8\u3067\u6a2a\u88c2\u3057\u30666\u88c2\u3057\u3001\u5e3d\u5b50\u72b6\u306e\u4e0a\u90e8\u304c\u8131\u843d\u3059\u308b\u3053\u3068\u306b\u3088\u3063\u3066\u7279\u5fb4\u3065\u3051\u3089\u308c\u308b\uff08\u4e0a\u56f3\u77e2\u5370\uff09\u3002 <\/p>\n\n\n\n

The flowers of the genus Calyptrotheca<\/em> consist of two sepals and five petals. However, as discussed for Portulacaria<\/em>, it is unclear whether the two outermost floral organs should be interpreted as bracts or as sepals. The stamens may number as many as about 60, and a single style elongates prominently, giving the flowers a resemblance to those of Capparaceae. As indicated by the generic name, which means \u201ca lidded container,\u201d this genus is characterized by capsules that split transversely near the base, divide into six lobes, and shed the cap-like upper portion (arrow in the figure above).<\/p>\n\n\n\n

\"\"<\/a>
\u30ab\u30ca\u30dc\u30a6\u30ce\u30ad\u4e9c\u79d1\u00a0 Didiereoideae<\/strong>
Rauh, W. (1983). The morphology and systematic position of the Didiereaceae of\u00a0 Madagascar. Bothalia 14<\/em>, 839\u2013843. https:\/\/doi.org\/10.4102\/ABC.V14I3\/4.1251.<\/figcaption><\/figure>\n\n\n\n

\u30ab\u30ca\u30dc\u30a6\u30ce\u30ad\u4e9c\u79d1<\/strong>  Didiereoideae<\/strong><\/p>\n\n\n\n

\u30ab\u30ca\u30dc\u30a6\u30ce\u30ad\u4e9c\u79d1 Didiereoideae \u306f\u3001\u30de\u30c0\u30ac\u30b9\u30ab\u30eb\u5357\u90e8\u304b\u3089\u5357\u897f\u90e8\u306b\u5206\u5e03\u3057\u3001\u30c8\u30a6\u30c0\u30a4\u30b0\u30b5\u5c5e\u690d\u7269\u3068\u3068\u3082\u306b\u3001Euphorbia\u2013Didiereaceae bush \u3068\u547c\u3070\u308c\u308b\u7279\u5fb4\u7684\u306a\u6709\u523a\u4f4e\u6728\u6797\uff08\u4e0a\u56f3\u306e\u659c\u7dda\u90e8\uff09\u3092\u5f62\u6210\u3059\u308b\uff08Rauh 1983\uff09\u3002<\/p>\n\n\n\n

The subfamily Didiereoideae is distributed from southern to southwestern Madagascar and, together with species of Euphorbia<\/em>, forms the characteristic spiny thicket known as Euphorbia\u2013Didiereaceae bush (hatched area in the figure above) (Rauh 1983).<\/p>\n\n\n\n

\"\"<\/a>
\u30ab\u30ca\u30dc\u30a6\u30ce\u30ad\u4e9c\u79d1 Didiereoideae \u306e\u7279\u5fb4\u00a0 Characteristics of the subfamily Didiereoideae<\/strong><\/figcaption><\/figure>\n\n\n\n

\u30ab\u30ca\u30dc\u30a6\u30ce\u30ad\u4e9c\u79d1 Didiereoideae \u306e\u7279\u5fb4\u00a0 Characteristics of the subfamily Didiereoideae<\/strong><\/p>\n\n\n\n

\u30ab\u30ca\u30dc\u30a6\u30ce\u30ad\u4e9c\u79d1 Didiereoideae \u306e4\u5c5e\u306f\u3001\u9577\u679d\u306e\u8449\u814b\u306b\u751f\u3058\u308b\u814b\u82bd\u306b\u7531\u6765\u3059\u308b\u30b7\u30e5\u30fc\u30c8\u306e\u767a\u751f\u521d\u671f\u306b\u5f62\u6210\u3055\u308c\u308b\u8449\u3001\u3059\u306a\u308f\u3061\u521d\u671f\u8449\u304c\u523a\u5316\u3059\u308b\u3053\u3068\u3092\u7279\u5fb4\u3068\u3059\u308b\u3002\u307e\u305f\u30014\u6570\u6027\u306e\u82b1\u88ab\u304a\u3088\u3073\u96cc\u96c4\u7570\u682a\u3082\u5171\u6709\u6d3e\u751f\u5f62\u8cea\u3068\u8003\u3048\u3089\u308c\u308b\u3002<\/p>\n\n\n\n

\u523a\u5316\u3059\u308b\u521d\u671f\u8449\u306e\u4f4d\u7f6e\u304a\u3088\u3073\u6570\u306f\u5c5e\u306b\u3088\u3063\u3066\u7570\u306a\u308b (Rauh 1956)\u3002\u30a2\u30e9\u30a6\u30c7\u30a3\u30aa\u30d7\u30b7\u30b9\u5c5e Alluaudiopsis<\/em> \u3067\u306f\u3001\u77ed\u679d\u3068\u306a\u308b\u814b\u82bd\u306b\u304a\u3044\u3066\u3001\u80cc\u8ef8\u5074\u306e1\u679a\u306e\u521d\u671f\u8449\u304c\u523a\u5316\u3059\u308b\u3002\u30c7\u30ab\u30ea\u30a2\u5c5e Decarya<\/em> \u3067\u306f\u3001\u814b\u82bd\u306e\u5bfe\u751f\u3059\u308b2\u679a\u306e\u521d\u671f\u8449\u304c\u523a\u5316\u3059\u308b\u3002\u30ab\u30ca\u30dc\u30a6\u30ce\u30ad\u5c5e Didierea<\/em> \u3067\u306f\u3001\u77ed\u679d\u3068\u306a\u308b\u814b\u82bd\u306b\u304a\u3044\u3066\u3001\u6570\u679a\u306e\u521d\u671f\u8449\u304c\u523a\u5316\u3059\u308b\u3002\u30a2\u30eb\u30a2\u30a6\u30c7\u30a3\u30a2\u5c5e Alluaudia<\/em> \u3067\u306f\u3001\u77ed\u679d\u3068\u306a\u308b\u814b\u82bd\u306b\u304a\u3044\u3066\u3001\u5411\u8ef8\u5074\u306e1\u679a\u306e\u521d\u671f\u8449\u304c\u523a\u5316\u3059\u308b\u3002<\/p>\n\n\n\n

The four genera of the subfamily Didiereoideae are characterized by the modification into spines of leaves formed early in the development of shoots derived from axillary buds in the axils of long-shoot leaves, that is, the early leaves. A tetramerous perianth and dioecy are also considered to be synapomorphies.<\/p>\n\n\n\n

The position and number of early leaves modified into spines differ among genera (Rauh 1956). In Alluaudiopsis<\/em>, a single early leaf on the abaxial side of the axillary bud that develops into a short shoot is modified into a spine. In Decarya<\/em>, two opposite early leaves of the axillary bud are modified into spines. In Didierea<\/em>, several early leaves of the axillary bud that develops into a short shoot are modified into spines. In Alluaudia<\/em>, a single early leaf on the adaxial side of the axillary bud that develops into a short shoot is modified into a spine.<\/p>\n\n\n\n

\"\"<\/a>
\u30ab\u30ca\u30dc\u30a6\u30ce\u30ad\u4e9c\u79d1 Didiereoideae \u306e\u523a\u306e\u9069\u5fdc\u7684\u610f\u7fa9\u00a0 Adaptive significance of spines in the subfamily Didiereoideae<\/strong><\/figcaption><\/figure>\n\n\n\n

\u30ab\u30ca\u30dc\u30a6\u30ce\u30ad\u4e9c\u79d1<\/strong> Didiereoideae <\/strong>\u306e\u523a\u306e\u9069\u5fdc\u7684\u610f\u7fa9<\/strong>  <\/strong>Adaptive significance of spines in the subfamily Didiereoideae<\/strong><\/p>\n\n\n\n

\u30ab\u30ca\u30dc\u30a6\u30ce\u30ad\u4e9c\u79d1 Didiereoideae \u306e\u523a\u306f\u3001\u52d5\u7269\u306b\u3088\u308b\u88ab\u98df\u306b\u5bfe\u3059\u308b\u9632\u5fa1\u3068\u8003\u3048\u3089\u308c\u308b\u3002\u3057\u304b\u3057\u3001\u5199\u771f\u306b\u793a\u3059\u3088\u3046\u306b\u3001\u73fe\u751f\u306e\u30ad\u30c4\u30cd\u30b6\u30eb\u985e\u306b\u5bfe\u3057\u3066\u306f\u3001\u5fc5\u305a\u3057\u3082\u9ad8\u3044\u9632\u5fa1\u52b9\u679c\u3092\u793a\u3059\u308f\u3051\u3067\u306f\u306a\u3044\u3002\u30d9\u30ec\u30f3\u30c6\u30a3\u4fdd\u8b77\u533a Berenty Private Reserve \u3067\u306f\u3001Lepilemur leucopus<\/em> \u304c\u4e7e\u5b63\u306e\u98df\u7269\u3092\u30a2\u30eb\u30a2\u30a6\u30c7\u30a3\u30a2\u5c5e Alluaudia<\/em> \u306e\u7a2e\u306e\u8449\u306b\u5927\u304d\u304f\u4f9d\u5b58\u3057\u3066\u3044\u308b (Crowley and Godfrey 2013)\u3002<\/p>\n\n\n\n

\u30ab\u30ca\u30dc\u30a6\u30ce\u30ad\u4e9c\u79d1\u304c\u4ed6\u306e\u4e9c\u79d1\u304b\u3089\u5206\u5c90\u3057\u305f\u306e\u306f\u7d041500\u4e07\u5e74\u524d\u3067\u3042\u308a\u3001\u305d\u306e\u5f8c\u3001\u30a2\u30d5\u30ea\u30ab\u304b\u3089\u30de\u30c0\u30ac\u30b9\u30ab\u30eb\u3078\u7956\u5148\u304c\u9577\u8ddd\u96e2\u5206\u6563\u3057\u3001\u5cf6\u5185\u3067\u591a\u69d8\u5316\u3057\u305f\u3068\u63a8\u5b9a\u3055\u308c\u3066\u3044\u308b (Ocampo and Columbus 2010)\u3002\u305d\u306e\u6642\u4ee3\u306e\u30de\u30c0\u30ac\u30b9\u30ab\u30eb\u306b\u5b58\u5728\u3057\u305f\u5927\u578b\u690d\u98df\u52d5\u7269\u3068\u3057\u3066\u306f\u3001\u5316\u77f3\u8a18\u9332\u306b\u57fa\u3065\u304d\u3001\u30a8\u30d4\u30aa\u30eb\u30cb\u30b9\u985e (\u30be\u30a6\u30c1\u30e7\u30a6\u985e) \u3068\u30ad\u30c4\u30cd\u30b6\u30eb\u985e\u306e\u307f\u304c\u60f3\u5b9a\u3055\u308c\u3066\u3044\u308b\u3002\u30a8\u30d4\u30aa\u30eb\u30cb\u30b9\u985e\u306f\u5927\u304d\u304f\u786c\u3044\u304f\u3061\u3070\u3057\u3092\u3082\u3063\u3066\u3044\u305f\u305f\u3081\u3001\u523a\u306b\u3088\u308b\u9632\u5fa1\u52b9\u679c\u306f\u9650\u5b9a\u7684\u3067\u3042\u3063\u305f\u3068\u8003\u3048\u3089\u308c\u308b (Crowley and Godfrey 2013)\u3002<\/p>\n\n\n\n

\u305d\u306e\u305f\u3081\u3001\u30ab\u30ca\u30dc\u30a6\u30ce\u30ad\u4e9c\u79d1\u306e\u521d\u671f\u9032\u5316\u6bb5\u968e\u3067\u306f\u3001\u523a\u306f\u5f53\u6642\u306e\u30ad\u30c4\u30cd\u30b6\u30eb\u985e\u306b\u5bfe\u3059\u308b\u9632\u5fa1\u3068\u3057\u3066\u6a5f\u80fd\u3057\u3066\u3044\u305f\u304c\u3001\u305d\u306e\u5f8c\u3001\u30ad\u30c4\u30cd\u30b6\u30eb\u985e\u304c\u523a\u306e\u3042\u308b\u690d\u7269\u3092\u5229\u7528\u3067\u304d\u308b\u3088\u3046\u306b\u9032\u5316\u3057\u305f\u53ef\u80fd\u6027\u304c\u3042\u308b\u3068\u63a8\u5b9a\u3055\u308c\u3066\u3044\u308b (Crowley and Godfrey 2013)\u3002<\/p>\n\n\n\n

The spines of the subfamily Didiereoideae are thought to function as a defense against herbivory. However, as shown in the photograph, they do not necessarily provide strong protection against extant lemurs. In Berenty Private Reserve, Lepilemur leucopus<\/em> relies heavily on the leaves of species of Alluaudia<\/em> as a food source during the dry season (Crowley and Godfrey 2013).<\/p>\n\n\n\n

Didiereoideae is estimated to have diverged from the other subfamilies approximately 15 million years ago, after which its ancestor dispersed from Africa to Madagascar by long-distance dispersal and diversified on the island (Ocampo and Columbus 2010). Based on the fossil record, the only large herbivores inferred to have been present in Madagascar at that time were elephant birds and lemurs. Because elephant birds had large, hard beaks, the defensive effect of spines against them is thought to have been limited (Crowley and Godfrey 2013). Thus, it has been suggested that, during the early evolution of Didiereoideae, the spines functioned as a defense against lemurs present at that time, but that lemurs subsequently evolved the ability to exploit spiny plants (Crowley and Godfrey 2013).<\/p>\n\n\n\n

\"\"<\/a>
\u30ab\u30ca\u30dc\u30a6\u30ce\u30ad\u4e9c\u79d1 Didiereoideae \u306e\u85ea\u72b6\u5f62\u614b\u306e\u9069\u5fdc\u7684\u610f\u7fa9\u00a0 Adaptive significance of the bushy habit in the subfamily Didiereoideae<\/strong>
Alluaudiopsis fiherenensis<\/em>_1: cropped a photo by Solofo Eric Rakotoarisoa, https:\/\/www.inaturalist.org\/photos\/106738053, CC BY-NC
Alluaudia comosa<\/em>_1: cropped a photo by Joshua Stone, https:\/\/www.inaturalist.org\/photos\/675711888, CC BY-NC
Decarya madagascariensis<\/em>_1: cropped a photo by Franck Rakotonasolo, https:\/\/www.inaturalist.org\/photos\/2041841, CC BY-NC<\/figcaption><\/figure>\n\n\n\n

\u30ab\u30ca\u30dc\u30a6\u30ce\u30ad\u4e9c\u79d1<\/strong> Didiereoideae <\/strong>\u306e\u85ea\u72b6\u5f62\u614b\u306e\u9069\u5fdc\u7684\u610f\u7fa9<\/strong>  <\/strong>Adaptive significance of the bushy habit in the subfamily Didiereoideae<\/strong><\/p>\n\n\n\n

\u30a2\u30e9\u30a6\u30c7\u30a3\u30aa\u30d7\u30b7\u30b9\u5c5e Alluaudiopsis<\/em> \u3068\u30a2\u30eb\u30a2\u30a6\u30c7\u30a3\u30a2\u5c5e Alluaudia<\/em> \u306e\u7a2e\u306f\u3001\u751f\u80b2\u521d\u671f\u306b\u306f\u5f3e\u529b\u6027\u306e\u3042\u308b\u679d\u3092\u3082\u3061\u3001\u5e83\u89d2\u306b\u5206\u679d\u3059\u308b\u85ea\u72b6\u306e\u5f62\u614b\u3092\u793a\u3059\u3002\u307e\u305f\u3001\u30c7\u30ab\u30ea\u30a2\u5c5e Decarya<\/em> \u306e\u7a2e\u306f\u3001\u6210\u9577\u5f8c\u3082\u85ea\u72b6\u306e\u5f62\u614b\u3092\u4fdd\u3064\u3002\u3053\u308c\u3089\u306e\u5f62\u614b\u306f\u3001\u9678\u30ac\u30e1\u985e\u3001\u30ab\u30d0\u985e\u3001\u30ad\u30c4\u30cd\u30b6\u30eb\u985e\u306a\u3069\u306e\u690d\u98df\u52d5\u7269\u306b\u5bfe\u3057\u3066\u306f\u3001\u305d\u308c\u307b\u3069\u9ad8\u3044\u9632\u5fa1\u52b9\u679c\u3092\u793a\u3055\u306a\u3044\u3068\u8003\u3048\u3089\u308c\u308b (Crowley and Godfrey 2013)\u3002\u4e00\u65b9\u3001\u7d76\u6ec5\u3057\u305f\u30a8\u30d4\u30aa\u30eb\u30cb\u30b9\u985e\u306b\u3068\u3063\u3066\u306f\u3001\u5927\u304d\u306a\u304f\u3061\u3070\u3057\u3067\u5f3e\u529b\u6027\u306e\u3042\u308b\u679d\u306e\u85ea\u306e\u4e2d\u304b\u3089\u8449\u3092\u98df\u3079\u308b\u3053\u3068\u306f\u56f0\u96e3\u3067\u3042\u308a\u3001\u9632\u5fa1\u52b9\u679c\u304c\u3042\u3063\u305f\u3068\u8003\u3048\u3089\u308c\u3066\u3044\u308b(Bond and Silander 2007)\u3002\u73fe\u5728\u3067\u306f\u3001\u30a8\u30d4\u30aa\u30eb\u30cb\u30b9\u985e\u306e\u7d76\u6ec5\u306b\u4f34\u3044\u3001\u3053\u308c\u3089\u306e\u5f62\u614b\u306f\u9032\u5316\u7684\u30a2\u30ca\u30af\u30ed\u30cb\u30ba\u30e0\u3001\u3059\u306a\u308f\u3061\u7d76\u6ec5\u3057\u305f\u751f\u7269\u3068\u306e\u76f8\u4e92\u4f5c\u7528\u306b\u7531\u6765\u3059\u308b\u9069\u5fdc\u5f62\u8cea\u306e\u540d\u6b8b\u3067\u3042\u308b\u53ef\u80fd\u6027\u304c\u3042\u308b\u3068\u8003\u3048\u3089\u308c\u3066\u3044\u308b (Crowley and Godfrey 2011; Bond and Silander 2007)\u3002\u540c\u69d8\u306b\u3001\u5927\u578b\u306e\u98db\u3079\u306a\u3044\u9ce5\u985e\u3067\u3042\u308b\u30e2\u30a2\u985e\u304c\u7d76\u6ec5\u3057\u305f\u30cb\u30e5\u30fc\u30b8\u30fc\u30e9\u30f3\u30c9\u3067\u3082\u3001\u4f3c\u305f\u679d\u3076\u308a\u3092\u3082\u3064\u690d\u7269\u304c\u898b\u3089\u308c\u3001\u305d\u308c\u3089\u3082\u9032\u5316\u7684\u30a2\u30ca\u30af\u30ed\u30cb\u30ba\u30e0\u3068\u8003\u3048\u3089\u308c\u3066\u3044\u308b (Bond and Silander 2007)\u3002 <\/p>\n\n\n\n

Species of Alluaudiopsis<\/em> and Alluaudia<\/em> have elastic branches during early growth and show a bushy habit with widely divergent branching. Species of Decarya<\/em> also retain a bushy habit even when mature. These forms are thought to provide relatively little protection against herbivores such as tortoises, hippos, and lemurs (Crowley and Godfrey 2013). By contrast, for the extinct elephant birds, it would have been difficult to feed on leaves from within a thicket of elastic branches using their large beaks, and these forms are therefore thought to have had a defensive function against them (Bond and Silander 2007). Today, following the extinction of elephant birds, these forms may represent evolutionary anachronisms, that is, remnants of adaptive traits derived from interactions with extinct organisms (Crowley and Godfrey 2011; Bond and Silander 2007). Similarly, in New Zealand, where moas, large flightless birds, have gone extinct, plants with similar branching patterns are found and are also regarded as evolutionary anachronisms (Bond and Silander 2007).<\/p>\n\n\n\n

\"\"<\/a>
\u30a2\u30eb\u30a2\u30a6\u30c7\u30a3\u30aa\u30d7\u30b7\u30b9\u5c5e Alluaudiopsis<\/em> \u306e\u7279\u5fb4\u00a0 Characteristics of the genus Alluaudiopsis<\/em><\/strong><\/figcaption><\/figure>\n\n\n\n

\u30a2\u30eb\u30a2\u30a6\u30c7\u30a3\u30aa\u30d7\u30b7\u30b9\u5c5e <\/strong>Alluaudiopsis<\/em><\/strong> <\/strong>\u306e\u7279\u5fb4<\/strong>  <\/strong>Characteristics of the genus <\/strong>Alluaudiopsis<\/em><\/strong><\/p>\n\n\n\n

\u30a2\u30eb\u30a2\u30a6\u30c7\u30a3\u30aa\u30d7\u30b7\u30b9\u5c5e Alluaudiopsis<\/em> \u306f\u3001\u9577\u679d\u306e\u8449\u814b\u306b\u751f\u3058\u308b\u814b\u82bd\u306b\u304a\u3044\u3066\u3001\u80cc\u8ef8\u5074\u3001\u3059\u306a\u308f\u3061\u9577\u679d\u306e\u57fa\u90e8\u5074\u306b\u4f4d\u7f6e\u3059\u308b1\u679a\u306e\u521d\u671f\u8449\u304c\u523a\u5316\u3059\u308b\u3053\u3068\u3092\u7279\u5fb4\u3068\u3059\u308b\u3002<\/p>\n\n\n\n

The genus Alluaudiopsis<\/em> is characterized by the modification into a spine of a single early leaf located on the abaxial side of the axillary bud formed in the axil of a long-shoot leaf.<\/p>\n\n\n\n

\"\"<\/a>
\u30a2\u30eb\u30a2\u30a6\u30c7\u30a3\u30aa\u30d7\u30b7\u30b9\u5c5e Alluaudiopsis<\/em> \u2013 1. \u8349\u59ff\u00a0 Alluaudiopsis <\/em>\u2013 1. Habit<\/strong>
Alluaudiopsis fiherenensis<\/em>_1: cropped a photo by CORDENOS Thierry, https:\/\/www.inaturalist.org\/photos\/463788613, CC BY-NC
Alluaudiopsis marnieriana<\/em>_1: cropped a photo by Rosario Douglas, https:\/\/www.inaturalist.org\/photos\/438170892, CC BY<\/figcaption><\/figure>\n\n\n\n

\u30a2\u30eb\u30a2\u30a6\u30c7\u30a3\u30aa\u30d7\u30b7\u30b9\u5c5e <\/strong>Alluaudiopsis<\/em><\/strong> \u2013 1. <\/strong>\u8349\u59ff<\/strong>  <\/strong>Alluaudiopsis <\/em><\/strong>\u2013 1. Habit<\/strong><\/p>\n\n\n\n

\u30a2\u30eb\u30a2\u30a6\u30c7\u30a3\u30aa\u30d7\u30b7\u30b9\u5c5e Alluaudiopsis<\/em> \u306f\u3001\u30de\u30c0\u30ac\u30b9\u30ab\u30eb\u5357\u90e8\u304b\u3089\u5357\u897f\u90e8\u306b\u5206\u5e03\u3059\u308b2\u7a2e\u304b\u3089\u306a\u308b\uff08POWO\uff09\u3002\u85ea\u72b6\u307e\u305f\u306f\u4f4e\u6728\u72b6\u306e\u690d\u7269\u3067\u3042\u308b (Kubitzki 1993)\u3002<\/p>\n\n\n\n

The genus Alluaudiopsis<\/em> comprises two species distributed from southern to southwestern Madagascar (POWO). They are bushy or shrubby plants (Kubitzki 1993).<\/p>\n\n\n\n

\"\"<\/a>
\u30a2\u30eb\u30a2\u30a6\u30c7\u30a3\u30aa\u30d7\u30b7\u30b9\u5c5e Alluaudiopsis<\/em> \u2013 2. \u830e\u8449\u00a0 Alluaudiopsis <\/em>\u2013 2. Stems and Leaves<\/strong><\/figcaption><\/figure>\n\n\n\n

\u30a2\u30eb\u30a2\u30a6\u30c7\u30a3\u30aa\u30d7\u30b7\u30b9\u5c5e <\/strong>Alluaudiopsis<\/em><\/strong> \u2013 2. <\/strong>\u830e\u8449<\/strong>  <\/strong>Alluaudiopsis <\/em><\/strong>\u2013 2. Stems and Leaves<\/strong><\/p>\n\n\n\n

\u30a2\u30eb\u30a2\u30a6\u30c7\u30a3\u30aa\u30d7\u30b7\u30b9\u5c5e Alluaudiopsis<\/em> \u306e\u7a2e\u3067\u306f\u3001\u9577\u679d\u306b\u3064\u304f\u8089\u8cea\u8449\uff08\u767d\u8272\u77e2\u5370\uff09\u306e\u814b\u82bd\u304c\u77ed\u679d\u3068\u306a\u308b\u3002\u305d\u306e\u77ed\u679d\u3067\u306f\u3001\u80cc\u8ef8\u5074\u3001\u3059\u306a\u308f\u3061\u9577\u679d\u306e\u57fa\u90e8\u5074\u306b\u4f4d\u7f6e\u3059\u308b1\u679a\u306e\u521d\u671f\u8449\u304c\u523a\uff08\u9752\u8272\u77e2\u5370\uff09\u3078\u3068\u5909\u5f62\u3059\u308b\u305f\u3081\u3001\u77ed\u679d\u306e\u9802\u7aef\u5206\u88c2\u7d44\u7e54\uff08\u8d64\u8272\u77e2\u5370\uff09\u306f\u523a\u3088\u308a\u3082\u9577\u679d\u306e\u5148\u7aef\u5074\u306b\u4f4d\u7f6e\u3059\u308b\u3002\u3053\u306e\u9802\u7aef\u5206\u88c2\u7d44\u7e54\u304b\u3089\u3001\u8089\u8cea\u306e\u6804\u990a\u8449\uff08\u6a59\u8272\u77e2\u5370\uff09\u304c\u5f62\u6210\u3055\u308c\u308b\u3002<\/p>\n\n\n\n

In species of Alluaudiopsis<\/em>, the axillary bud of a succulent leaf on the long shoot (white arrows) develops into a short shoot. In this short shoot, a single early leaf located on the abaxial side, that is, toward the base of the long shoot, is modified into a spine (blue arrows). As a result, the apical meristem of the short shoot (red arrows) is positioned distal to the spine, toward the apex of the long shoot. Succulent foliage leaves (orange arrows) are formed from this apical meristem.<\/p>\n\n\n\n

\"\"<\/a>
Alluaudiopsis fiherenensis<\/em>_2: cropped a photo by James Bailey, https:\/\/www.inaturalist.org\/photos\/662501361, CC BY-NC<\/figcaption><\/figure>\n\n\n\n

\u9577\u679d\u306e\u8449\u304c\u843d\u8449\u3057\u305f\u5f8c\u306f\u3001\u751f\u80b2\u671f\u3054\u3068\u306b\u77ed\u679d\u304b\u3089\u65b0\u3057\u3044\u8449\u304c\u5f62\u6210\u3055\u308c\u308b\u3002\u5199\u771f\u306b\u898b\u3048\u308b\u8449\u306f\u3059\u3079\u3066\u77ed\u679d\u306e\u8449\u3067\u3042\u308b\u3002<\/p>\n\n\n\n

After the leaves on the long shoots fall, new leaves are produced from the short shoots during each growing season. All the leaves visible in the photograph are short-shoot leaves.<\/p>\n\n\n\n

\"\"<\/a>
\u30a2\u30eb\u30a2\u30a6\u30c7\u30a3\u30aa\u30d7\u30b7\u30b9\u5c5e Alluaudiopsis<\/em> \u2013 3. \u82b1\u5e8f\u3068\u82b1\u00a0 Alluaudiopsis <\/em>\u2013 3. Inflorescences and Flowers<\/strong>
Alluaudiopsis marnieriana<\/em>_2: cropped a photo by Rob C. H. M. Oudejans, https:\/\/www.inaturalist.org\/photos\/58429619, CC BY-NC
Alluaudiopsis marnieriana<\/em>_3: cropped a photo by Laurence Ramon, https:\/\/www.inaturalist.org\/photos\/399348908, CC BY-NC
Alluaudiopsis marnieriana<\/em>_4: cropped a photo by Andy Goerdel – Texas Master Naturalist, Good Water Chapter, https:\/\/www.inaturalist.org\/photos\/586700401, CC BY-NC
Alluaudiopsis fiherenensis<\/em>_3: cropped a photo by nomentsoa, https:\/\/www.inaturalist.org\/photos\/592575626, CC BY-NC
Rauh, W. (1963). 121 Famille. Didiereacees. In Flore de Madagascar et des Comores: plantes vasculaires, , H. Humbert and J.-F. Leroy, eds. (Museum National D\u2019Histoire Naturelle). CC BY-NC-SA 4.0<\/figcaption><\/figure>\n\n\n\n

\u30a2\u30eb\u30a2\u30a6\u30c7\u30a3\u30aa\u30d7\u30b7\u30b9\u5c5e <\/strong>Alluaudiopsis<\/em><\/strong> \u2013 3. <\/strong>\u82b1\u5e8f\u3068\u82b1<\/strong>  <\/strong>Alluaudiopsis <\/em><\/strong>\u2013 3. Inflorescences and Flowers<\/strong><\/p>\n\n\n\n

\u30ab\u30ca\u30dc\u30a6\u30ce\u30ad\u4e9c\u79d1 Didiereoideae \u306e4\u5c5e\u306f\u3044\u305a\u308c\u3082\u3001\u53f3\u4e0a\u5199\u771f\u306b\u793a\u3059\u3088\u3046\u306b\u3001\u5bfe\u751f\u3059\u308b\u82de\u8449\u3092\u3082\u3061\u30012\u679a\u306e\u5916\u82b1\u88ab\u7247\u30682\u679a\u306e\u5185\u82b1\u88ab\u7247\u3092\u5f62\u6210\u3059\u308b\uff08Erbar and Leins 2006\uff09\u3002\u30dd\u30fc\u30c1\u30e5\u30e9\u30ab\u30ea\u30a2\u4e9c\u79d1 Portulacarioideae \u304a\u3088\u3073\u30ab\u30ea\u30d7\u30c8\u30ed\u30c6\u30ab\u4e9c\u79d1 Calyptrothecoideae \u306b\u898b\u3089\u308c\u308b5\u6570\u6027\u306e\u82b1\u88ab\u304c\u7956\u5148\u5f62\u8cea\u3067\u3042\u308a\u3001\u30ab\u30ca\u30dc\u30a6\u30ce\u30ad\u4e9c\u79d1\u306e\u5171\u901a\u7956\u5148\u306b\u304a\u3044\u3066\u3001\u5404\u8f2a2\u6570\u6027\u306e\u82b1\u88ab\u304c\u9032\u5316\u3057\u305f\u3068\u63a8\u5b9a\u3055\u308c\u3066\u3044\u308b\uff08Erbar and Leins 2006\uff09\u3002\u96c4\u305a\u3044\u306f6\u201312\u672c\u30671\u8f2a\u3092\u306a\u3057\u3001\u305d\u306e\u3046\u30612\u672c\u304c\u5916\u82b1\u88ab\u7247\u3068\u3001\u5225\u306e2\u672c\u304c\u5185\u82b1\u88ab\u7247\u3068\u5bfe\u751f\u3059\u308b\u3053\u3068\u304c\u591a\u3044\uff08Erbar and Leins 2006\uff09\u3002\u82de\u8449\u306f\u5bbf\u5b58\u6027\u3067\u3001\u679c\u5b9f\u3092\u5305\u3080\u3002\u4e0a\u56f3\u306e Alluaudiopsis marnieriana<\/em> \u306e\u679c\u5b9f\u56f3\uff08Rauh 1963\uff09\u3067\u306f\u3001\u82de\u8449\u304c\u53d6\u308a\u9664\u304b\u308c\u3066\u3044\u308b\u3002<\/p>\n\n\n\n

All four genera of the subfamily Didiereoideae have opposite bracts and form two outer and two inner perianth segments, as shown in the upper right of the figure above (Erbar and Leins 2006). The pentamerous perianth found in Portulacarioideae and Calyptrothecoideae is inferred to represent the ancestral condition, and a perianth with two segments in each whorl is thought to have evolved in the common ancestor of Didiereoideae (Erbar and Leins 2006). The stamens number 6\u201312 and form a single whorl; two of them are often opposite the outer perianth segments and another two are often opposite the inner perianth segments (Erbar and Leins 2006). The bracts are persistent and enclose the fruit. In the fruit illustration of Alluaudiopsis marnieriana<\/em> shown above (Rauh 1963), the bracts have been removed.<\/p>\n\n\n\n

\"\"<\/a>
\u30c7\u30ab\u30ea\u30a2\u5c5e Decarya<\/em> \u306e\u7279\u5fb4\u00a0 Characteristics of the genus Decarya<\/em><\/strong><\/figcaption><\/figure>\n\n\n\n

\u30c7\u30ab\u30ea\u30a2<\/strong>\u5c5e<\/strong> <\/strong>Decarya<\/em><\/strong> <\/strong>\u306e\u7279\u5fb4<\/strong>  <\/strong>Characteristics of the genus <\/strong>Decarya<\/em><\/strong><\/p>\n\n\n\n

\u30c7\u30ab\u30ea\u30a2\u5c5e Decarya<\/em> \u3067\u306f\u3001\u9577\u679d\u306e\u8449\u814b\u306b\u751f\u3058\u308b\u814b\u82bd\u306b\u304a\u3044\u3066\u3001\u5bfe\u751f\u3059\u308b2\u679a\u306e\u521d\u671f\u8449\u304c\u523a\u5316\u3059\u308b\u3002\u814b\u82bd\u306f\u9577\u679d\u3068\u3057\u3066\u4f38\u9577\u3059\u308b\u5834\u5408\u3068\u3001\u4f38\u9577\u305b\u305a\u306b\u6d3b\u52d5\u3092\u505c\u6b62\u3059\u308b\u5834\u5408\u304c\u3042\u308a\u3001\u4ed6\u306e\u30ab\u30ca\u30dc\u30a6\u30ce\u30ad\u4e9c\u79d1\u306e\u5c5e\u306b\u898b\u3089\u308c\u308b\u3088\u3046\u306a\u5178\u578b\u7684\u306a\u77ed\u679d\u306f\u5f62\u6210\u3057\u306a\u3044\u3002\u307e\u305f\u3001\u9577\u679d\u304c\u30b8\u30b0\u30b6\u30b0\u72b6\u306b\u5c48\u66f2\u3059\u308b\u3053\u3068\u3082\u3001\u3053\u306e\u5c5e\u3092\u7279\u5fb4\u3065\u3051\u308b\u5f62\u8cea\u3067\u3042\u308b\u3002<\/p>\n\n\n\n

In the genus Decarya<\/em>, two opposite early leaves of the axillary bud formed in the axil of a long-shoot leaf are modified into spines. The axillary bud may elongate as a long shoot or cease activity without elongating, and it does not form a typical short shoot like those seen in other genera of Didiereoideae. The zigzag bending of the long shoots is also a characteristic feature of this genus.<\/p>\n\n\n\n

\"\"<\/a>
\u30c7\u30ab\u30ea\u30a2\u5c5e Decarya<\/em> \u2013 1. \u8349\u59ff\u00a0 Decarya <\/em>\u2013 1. Habit<\/strong>
Decarya madagascariensis<\/em>_1: cropped from a photo by mamy_andriamahay, https:\/\/www.inaturalist.org\/photos\/9358854, CC BY-NC
Decarya madagascariensis<\/em>_2: cropped from a photo by Laurence Ramon, https:\/\/www.inaturalist.org\/photos\/511816461, CC BY-NC<\/figcaption><\/figure>\n\n\n\n

\u30c7\u30ab\u30ea\u30a2<\/strong>\u5c5e<\/strong> <\/strong>Decarya<\/em><\/strong> \u2013 1. <\/strong>\u8349\u59ff<\/strong>  <\/strong>Decarya <\/em><\/strong>\u2013 1. Habit<\/strong><\/p>\n\n\n\n

\u30c7\u30ab\u30ea\u30a2\u5c5e Decarya<\/em> \u306f\u3001\u30de\u30c0\u30ac\u30b9\u30ab\u30eb\u5357\u90e8\u306b\u5206\u5e03\u3059\u308b1\u7a2e\u306e\u307f\u304b\u3089\u306a\u308b (POWO\uff09\u3002\u85ea\u72b6\u3001\u4f4e\u6728\u72b6\u3001\u307e\u305f\u306f\u5c0f\u9ad8\u6728\u72b6\u306b\u306a\u308b (Kubitzki 1993)\u3002 <\/p>\n\n\n\n

The genus Decarya<\/em> comprises a single species distributed in southern Madagascar (POWO). It is bushy, shrubby, or small-tree-like in habit (Kubitzki 1993).<\/p>\n\n\n\n

\"\"<\/a>
\u30c7\u30ab\u30ea\u30a2\u5c5e Decarya<\/em> \u2013 2. \u830e\u8449\u00a0 Decarya <\/em>\u2013 2. Stems and Leaves<\/strong><\/figcaption><\/figure>\n\n\n\n

\u30c7\u30ab\u30ea\u30a2<\/strong>\u5c5e<\/strong> <\/strong>Decarya<\/em><\/strong> \u2013 2. <\/strong>\u830e\u8449<\/strong>  <\/strong>Decarya <\/em><\/strong>\u2013 2. Stems and Leaves<\/strong><\/p>\n\n\n\n

\u30c7\u30ab\u30ea\u30a2\u5c5e Decarya<\/em> \u306e\u7a2e\u3067\u306f\u3001\u9577\u679d\u306b\u3064\u304f\u8089\u8cea\u8449\uff08\u767d\u8272\u77e2\u5370\uff09\u306f\u65e9\u843d\u6027\u3067\u3042\u308a\u3001\u305d\u306e\u8449\u814b\u306b\u814b\u82bd\u304c\u5f62\u6210\u3055\u308c\u308b\u3002\u3053\u306e\u814b\u82bd\u3067\u306f\u3001\u5bfe\u751f\u3059\u308b2\u679a\u306e\u521d\u671f\u8449\u304c\u523a (\u9752\u8272\u77e2\u5370) \u3078\u3068\u5909\u5f62\u3059\u308b\u305f\u3081\u3001\u814b\u82bd\u306e\u9802\u7aef\u5206\u88c2\u7d44\u7e54 (\u8d64\u8272\u77e2\u5370) \u306f2\u672c\u306e\u523a\u306e\u9593\u306b\u4f4d\u7f6e\u3059\u308b\u3002\u30c7\u30ab\u30ea\u30a2\u5c5e\u306e\u523a\u306f\u9577\u679d\u306e\u8449\u306e\u6258\u8449\u306e\u3088\u3046\u306b\u3082\u898b\u3048\u308b\u304c\u3001\u30ab\u30ca\u30dc\u30a6\u30ce\u30ad\u79d1\u306e\u4ed6\u306e\u5c5e\u3067\u306f\u6258\u8449\u304c\u5f62\u6210\u3055\u308c\u306a\u3044\u3053\u3068\u3001\u523a\u304c\u9577\u679d\u306e\u8449\u306e\u767a\u751f\u5f8c\u306b\u751f\u3058\u308b\u3053\u3068\u3001\u307e\u305f\u523a\u304c\u9577\u679d\u306e\u8449\u306e\u57fa\u90e8\u3088\u308a\u3082\u830e\u9802\u5074\u306b\u5f62\u6210\u3055\u308c\u308b\u3053\u3068\u304b\u3089\u3001\u814b\u82bd\u306b\u7531\u6765\u3059\u308b\u521d\u671f\u8449\u3067\u3042\u308b\u3068\u8003\u3048\u3089\u308c\u3066\u3044\u308b (Rauh 1960\/1961)\u3002<\/p>\n\n\n\n

\u30c7\u30ab\u30ea\u30a2\u5c5e\u3067\u306f\u3001\u9577\u679d\u306e\u8449\u306f\u4e92\u751f\u3059\u308b\u304c\u3001\u814b\u82bd\u306b\u7531\u6765\u3059\u308b\u523a\u306f\u5bfe\u751f\u3059\u308b\u3002\u814b\u82bd\u306e\u521d\u671f\u8449\u306e\u3046\u3061\u3001\u6700\u521d\u306b\u5f62\u6210\u3055\u308c\u308b1\u679a\u307e\u305f\u306f\u6570\u679a\u306f\u524d\u51fa\u8449 prophyll \u3068\u547c\u3070\u308c (Choob 2022)\u3001\u305d\u306e\u5f8c\u306b\u5f62\u6210\u3055\u308c\u308b\u8449\u3068\u306f\u8449\u5e8f\u3084\u5f62\u614b\u304c\u7570\u306a\u308b\u3053\u3068\u304c\u3042\u308b\u3002\u305d\u306e\u305f\u3081\u3001\u30c7\u30ab\u30ea\u30a2\u5c5e\u306e\u523a\u306f\u524d\u51fa\u8449\u3067\u3042\u308b\u53ef\u80fd\u6027\u304c\u3042\u308b\u30022\u679a\u306e\u523a\u8449\u3092\u5f62\u6210\u3057\u305f\u5f8c\u3001\u814b\u82bd\u306f\u9577\u679d\u3068\u3057\u3066\u4f38\u9577\u3059\u308b\u304b\u3001\u307e\u305f\u306f\u6d3b\u52d5\u3092\u505c\u6b62\u3057\u3001\u305d\u308c\u4ee5\u964d\u306e\u8449\u3092\u5f62\u6210\u3057\u306a\u3044 (Rauh 1960\/1961)\u3002<\/p>\n\n\n\n

In species of Decarya<\/em>, the succulent leaves on the long shoots (white arrows) are caducous, and axillary buds are formed in their axils. In these buds, two opposite early leaves are modified into spines (blue arrows), so that the apical meristem of the axillary bud (red arrow) is positioned between the two spines. Although the spines of Decarya<\/em> may appear similar to stipules of the long-shoot leaves, they are considered to be early leaves derived from axillary buds because stipules are not formed in other genera of Didiereaceae, because the spines arise after the initiation of the long-shoot leaves, and because they are formed distal to the bases of the long-shoot leaves, toward the shoot apex (Rauh 1960\/1961).<\/p>\n\n\n\n

In Decarya<\/em>, the leaves on the long shoots are alternate, whereas the spines derived from the axillary buds are opposite. The first one or several early leaves of an axillary bud are called prophylls (Choob 2022), and they may differ in phyllotaxis and morphology from leaves formed later. Therefore, the spines of Decarya<\/em> may represent prophylls. After forming two spine leaves, the axillary bud either elongates as a long shoot or ceases activity and forms no further leaves (Rauh 1960\/1961).<\/p>\n\n\n\n

\"\"<\/a><\/figure>\n\n\n\n

\u30c7\u30ab\u30ea\u30a2\u5c5e Decarya<\/em> \u306f\u3001\u4e0a\u306e\u5199\u771f\u306e\u3088\u3046\u306b\u3001\u9577\u679d\u306e\u5f62\u6210\u6642\u306b\u679d\u304c\u30b8\u30b0\u30b6\u30b0\u72b6\u306b\u4f38\u3073\u3001\u6210\u9577\u5f8c\u3082\u305d\u306e\u5f62\u72b6\u3092\u7dad\u6301\u3059\u308b\u3002<\/p>\n\n\n\n

\u30c7\u30ab\u30ea\u30a2\u5c5e\u306e\u30b8\u30b0\u30b6\u30b0\u72b6\u30b7\u30e5\u30fc\u30c8\u306e\u9069\u5fdc\u7684\u610f\u7fa9\u306f\u3001\u307e\u3060\u5b9f\u8a3c\u3055\u308c\u3066\u3044\u306a\u3044\u3002\u5148\u8ff0\u3057\u305f\u3088\u3046\u306b\u3001\u85ea\u72b6\u306e\u5f62\u614b\u3092\u3064\u304f\u308b\u3053\u3068\u3067\u3001\u4e7e\u71e5\u5730\u74b0\u5883\u306b\u304a\u3051\u308b\u88ab\u98df\u9632\u5fa1\u3068\u3057\u3066\u6a5f\u80fd\u3057\u3066\u3044\u308b\u53ef\u80fd\u6027\u304c\u3042\u308b\u3002\u307e\u305f\u3001\u9577\u679d\u8449\u304c\u77ed\u547d\u3067\u3001\u4e00\u5e74\u306e\u591a\u304f\u306e\u671f\u9593\u3092\u7121\u8449\u3067\u904e\u3054\u3059\u3053\u3068\u3092\u8003\u3048\u308b\u3068\u3001\u30b8\u30b0\u30b6\u30b0\u72b6\u306e\u679d\u306f\u3001\u830e\u306b\u3088\u308b\u5149\u5408\u6210\u9762\u7a4d\u306e\u78ba\u4fdd\u306b\u5bc4\u4e0e\u3057\u3066\u3044\u308b\u53ef\u80fd\u6027\u3082\u3042\u308b\u3002\u30b8\u30b0\u30b6\u30b0\u72b6\u306e\u679d\u304c\u767a\u751f\u7684\u306b\u3069\u306e\u3088\u3046\u306b\u5f62\u6210\u3055\u308c\u308b\u306e\u304b\u306b\u3064\u3044\u3066\u306f\u3001\u307e\u3060\u8abf\u3079\u3089\u308c\u3066\u3044\u306a\u3044\u3002<\/p>\n\n\n\n

In the genus Decarya<\/em>, as shown in the photograph above, branches elongate in a zigzag pattern during the formation of long shoots and retain this shape after maturation. The adaptive significance of the zigzag shoots in Decarya<\/em> has not yet been demonstrated. As discussed above, they may function as a defense against herbivory in arid environments by forming a bushy habit. In addition, because the long-shoot leaves are short-lived and the plants remain leafless for much of the year, the zigzag branches may also contribute to maintaining photosynthetic surface area in the stems. How these zigzag branches are formed developmentally has not yet been investigated.<\/p>\n\n\n\n

\"\"<\/a>
\u30c7\u30ab\u30ea\u30a2\u5c5e Decarya<\/em> \u2013 3. \u82b1\u5e8f\u3068\u82b1\u00a0 Decarya <\/em>\u2013 3. Inflorescences and Flowers<\/strong>
Decarya madagascariensis<\/em>_3: cropped from a photo by mamy_andriamahay, https:\/\/www.inaturalist.org\/photos\/9358854, CC BY-NC
Rauh, W. (1963). 121 Famille. Didiereacees. In Flore de Madagascar et des Comores: plantes vasculaires, , H. Humbert and J.-F. Leroy, eds. (Museum National D\u2019Histoire Naturelle). CC BY-NC-SA 4.0<\/figcaption><\/figure>\n\n\n\n

\u30c7\u30ab\u30ea\u30a2<\/strong>\u5c5e<\/strong> <\/strong>Decarya<\/em><\/strong> \u2013 3. <\/strong>\u82b1\u5e8f\u3068\u82b1<\/strong>  <\/strong>Decarya <\/em><\/strong>\u2013 3. Inflorescences and Flowers<\/strong><\/p>\n\n\n\n

\u30c7\u30ab\u30ea\u30a2\u5c5e Decarya<\/em> \u306e\u7a2e\u3067\u306f\u3001\u82b1\u306f\u5206\u679d\u3057\u305f\u96c6\u6563\u82b1\u5e8f\u306b\u3064\u304f\u3002\u4ed6\u306e\u30ab\u30ca\u30dc\u30a6\u30ce\u30ad\u4e9c\u79d1\u306e\u7a2e\u3068\u540c\u69d8\u306b\u3001\u5bfe\u751f\u3059\u308b2\u679a\u306e\u82de\u8449\u30012\u679a\u306e\u5916\u82b1\u88ab\u7247\u30682\u679a\u306e\u5185\u82b1\u88ab\u7247\u30018\u672c\u7a0b\u5ea6\u306e\u96c4\u305a\u3044\u3001\u304a\u3088\u30731\u672c\u306e\u96cc\u305a\u3044\u3092\u5f62\u6210\u3059\u308b\uff08Rauh 1963\uff09\u3002\u96c4\u82b1\u3067\u306f\u96cc\u305a\u3044\u304c\u3001\u96cc\u82b1\u3067\u306f\u96c4\u305a\u3044\u304c\u6210\u719f\u3057\u306a\u3044\uff08Rauh 1963\uff09\u3002 <\/p>\n\n\n\n

In species of Decarya<\/em>, the flowers are borne in branched cymose inflorescences. As in other species of Didiereoideae, each flower forms two opposite bracts, two outer and two inner perianth segments, about eight stamens, and a single pistil (Rauh 1963). In male flowers, the pistil does not mature, whereas in female flowers, the stamens do not mature (Rauh 1963).<\/p>\n\n\n\n

\"\"<\/a>
\u30ab\u30ca\u30dc\u30a6\u30ce\u30ad\u5c5e Didierea<\/em> \u306e\u7279\u5fb4\u00a0 Characteristics of the genus Didierea<\/em><\/strong><\/figcaption><\/figure>\n\n\n\n

\u30ab\u30ca\u30dc\u30a6\u30ce\u30ad<\/strong>\u5c5e<\/strong> <\/strong>Didierea<\/em><\/strong> <\/strong>\u306e\u7279\u5fb4<\/strong>  <\/strong>Characteristics of the genus <\/strong>Didierea<\/em><\/strong><\/p>\n\n\n\n

\u30ab\u30ca\u30dc\u30a6\u30ce\u30ad\u5c5e Didierea<\/em> \u3067\u306f\u3001\u9577\u679d\u306e\u8449\u814b\u306b\u751f\u3058\u308b\u814b\u82bd\u306b\u304a\u3044\u3066\u3001\u6570\u679a\u306e\u521d\u671f\u8449\u304c\u523a\u5316\u3057\u3001\u830e\u306e\u9ac4\u304c\u767a\u9054\u3057\u3001\u8caf\u6c34\u7d44\u7e54\u3068\u3057\u3066\u6a5f\u80fd\u3059\u308b\u3053\u3068\u3092\u7279\u5fb4\u3068\u3059\u308b\u3002 <\/p>\n\n\n\n

The genus Didierea<\/em> is characterized by the modification of several early leaves into spines in axillary buds formed in the axils of long-shoot leaves, and by the development of the stem pith as a water-storage tissue.<\/p>\n\n\n\n

\"\"<\/a>
\u30ab\u30ca\u30dc\u30a6\u30ce\u30ad\u5c5e Didierea<\/em> \u2013 1. \u8349\u59ff\u00a0 Didierea <\/em>\u2013 1. Habit<\/strong>
Didierea madagascariensis<\/em>_1: cropped a photo by Nick Leggatt, https:\/\/www.inaturalist.org\/photos\/681559740, CC BY-NC
Didierea trollii<\/em>_1: cropped a photo by Solofo Eric Rakotoarisoa, https:\/\/www.inaturalist.org\/photos\/18818029, CC BY-NC<\/figcaption><\/figure>\n\n\n\n

\u30ab\u30ca\u30dc\u30a6\u30ce\u30ad<\/strong>\u5c5e<\/strong> <\/strong>Didierea<\/em><\/strong> \u2013 1. <\/strong>\u8349\u59ff<\/strong>  <\/strong>Didierea <\/em><\/strong>\u2013 1. Habit<\/strong><\/p>\n\n\n\n

\u30ab\u30ca\u30dc\u30a6\u30ce\u30ad\u5c5e Didierea<\/em> \u306f\u3001\u30de\u30c0\u30ac\u30b9\u30ab\u30eb\u5357\u90e8\u304b\u3089\u5357\u897f\u90e8\u306b\u5206\u5e03\u3059\u308b2\u7a2e\u304b\u3089\u306a\u308b (POWO)\u3002\u9ad8\u3055\u6570m\u7a0b\u5ea6\u306b\u9054\u3059\u308b\u704c\u6728\u307e\u305f\u306f\u4f4e\u6728\u3067\u3042\u308b (Kubitzki 1993)\u3002D. trollii<\/em> \u306f\u3001\u82e5\u3044\u6642\u671f\u306b\u530d\u5310\u6027\u307e\u305f\u306f\u659c\u4e0a\u6027\u306e\u679d\uff08\u53f3\u56f3\u77e2\u5370\uff09\u3092\u5f62\u6210\u3059\u308b\u7279\u5fb4\u304c\u3042\u308b (Rauh 1963)\u3002 <\/p>\n\n\n\n

The genus Didierea<\/em> comprises two species distributed from southern to southwestern Madagascar (POWO). They are bushy or shrubby plants reaching several meters in height (Kubitzki 1993). D. trollii<\/em> is characterized by the formation of creeping or ascending branches during its juvenile stage (arrow in the figure on the right) (Rauh 1963).<\/p>\n\n\n\n

\"\"<\/a>
\u30ab\u30ca\u30dc\u30a6\u30ce\u30ad\u5c5e Didierea<\/em> \u2013 2. \u830e\u8449\u00a0 Didierea <\/em>\u2013 2. Stems and Leaves<\/strong><\/figcaption><\/figure>\n\n\n\n

\u30ab\u30ca\u30dc\u30a6\u30ce\u30ad<\/strong>\u5c5e<\/strong> <\/strong>Didierea<\/em><\/strong> \u2013 2. <\/strong>\u830e\u8449<\/strong>  <\/strong>Didierea <\/em><\/strong>\u2013 2. Stems and Leaves<\/strong><\/p>\n\n\n\n

\u30ab\u30ca\u30dc\u30a6\u30ce\u30ad\u5c5e Didierea<\/em> \u306e\u7a2e\u3067\u306f\u3001\u9577\u679d\u306b\u3064\u304f\u8089\u8cea\u8449 (\u767d\u8272\u77e2\u5370) \u306e\u814b\u82bd\u304c\u77ed\u679d\u3068\u306a\u308b\u3002\u3053\u306e\u77ed\u679d\u306b\u751f\u3058\u308b\u6570\u679a\u306e\u521d\u671f\u8449\u306f\u523a (\u9752\u8272\u77e2\u5370) \u3078\u3068\u5909\u5f62\u3057\u3001\u305d\u306e\u5f8c\u306b\u8089\u8cea\u8449 (\u6a59\u8272\u77e2\u5370) \u304c\u5f62\u6210\u3055\u308c\u308b\u3002\u5199\u771f\u3067\u306f\u523a\u306f3\u672c\u898b\u3048\u308b\u304c\u300112\u672c\u307b\u3069\u5f62\u6210\u3055\u308c\u308b\u3053\u3068\u3082\u3042\u308b (Kubitzki 1993)\u3002\u77ed\u679d\u306e\u9802\u7aef\u5206\u88c2\u7d44\u7e54\u306f\u3001\u3053\u308c\u3089\u306e\u523a\u3084\u8449\u306e\u4e2d\u592e\u306b\u4f4d\u7f6e\u3059\u308b\u3002\u523a\u306f\u814b\u82bd\u304c\u4f38\u9577\u3059\u308b\u6700\u521d\u306e\u5e74\u306b\u3060\u3051\u5f62\u6210\u3055\u308c\u308b\u3002\u8089\u8cea\u8449\u306f\u4e7e\u5b63\u306b\u843d\u8449\u3057\u3001\u96e8\u5b63\u306b\u306a\u308b\u3068\u77ed\u679d\u306e\u9802\u7aef\u5206\u88c2\u7d44\u7e54\u304b\u3089\u6570\u679a\u306e\u6804\u990a\u8449\u304c\u5f62\u6210\u3055\u308c\u308b (Rauh 1983)\u3002<\/p>\n\n\n\n

In species of Didierea<\/em>, the axillary buds of the succulent leaves on the long shoots (white arrow) develop into short shoots. Several early leaves formed on these short shoots are modified into spines (blue arrows), and succulent leaves (orange arrows) are formed subsequently. Although three spines are visible in the photograph, as many as about 12 may be formed (Kubitzki 1993). The apical meristem of the short shoot is located at the center of these spines and leaves. Spines are formed only in the first year of axillary-bud elongation. The succulent leaves fall during the dry season, and when the rainy season begins, several vegetative leaves are formed from the apical meristem of the short shoot (Rauh 1983).<\/p>\n\n\n\n

\"\"<\/a><\/figure>\n\n\n\n

\u9577\u679d\u306e\u8089\u8cea\u8449 (\u9ec4\u8272\u77e2\u5370) \u306e\u3059\u3079\u3066\u306e\u8449\u814b\u304b\u3089\u77ed\u679d\u304c\u5f62\u6210\u3055\u308c\u308b\u3002\u9577\u679d\u306e\u8089\u8cea\u8449\u306f\u65e9\u843d\u6027\u3067\u3042\u308a\u3001\u5199\u771f\u3067\u306f\u3059\u3067\u306b\u307b\u3068\u3093\u3069\u304c\u843d\u8449\u3057\u3066\u3001\u8449\u75d5 (\u767d\u8272\u77e2\u5370) \u304c\u898b\u3048\u3066\u3044\u308b\u3002\u7fcc\u5e74\u4ee5\u964d\u306e\u96e8\u5b63\u306b\u306f\u3001\u77ed\u679d\u306e\u8449\u306e\u307f\u304c\u5f62\u6210\u3055\u308c\u308b\u3002<\/p>\n\n\n\n

Short shoots are formed in all axils of the succulent leaves on the long shoots (yellow arrow). The succulent leaves on the long shoots are caducous, and in the photograph most have already fallen, leaving visible leaf scars (white arrows). In the rainy seasons from the following year onward, only leaves of the short shoots are formed.<\/p>\n\n\n\n

\"\"<\/a><\/figure>\n\n\n\n

\u77ed\u679d\u3092\u830e\u9802\u5074\u304b\u3089\u898b\u305f\u69d8\u5b50 (\u5de6\u5199\u771f)\u3002\u77ed\u679d\u306e\u9802\u7aef\u5206\u88c2\u7d44\u7e54\u306f\u3001\u523a\u3084\u8449\u306b\u56f2\u307e\u308c\u305f\u4e2d\u592e\u90e8\u306b\u4f4d\u7f6e\u3059\u308b\u3002\u524d\u51fa\u8449\u3067\u3042\u308b\u523a\u3068\u3001\u305d\u306e\u5f8c\u306b\u5f62\u6210\u3055\u308c\u308b\u8089\u8cea\u306e\u6804\u990a\u8449\u306f\u3001\u3068\u3082\u306b\u8449\u5e8f\u3092\u69cb\u6210\u3059\u308b\u3002\u830e\u9802\u5206\u88c2\u7d44\u7e54 (\u53f3\u5199\u771f\u3001\u9ed2\u8272\u77e2\u5370) \u306f\u3001\u8449\u57fa\u306e\u5965\u306b\u6c88\u307f\u8fbc\u3093\u3067\u3044\u308b\u3002 <\/p>\n\n\n\n

Short shoot viewed from the apical side (left photograph). The apical meristem of the short shoot is located in the central region surrounded by the spines and leaves. The spines, which are prophylls, and the succulent vegetative leaves formed subsequently together constitute the phyllotaxis. The shoot apical meristem (right photograph, black arrow) is sunken deep among the leaf bases.<\/p>\n\n\n\n

\"\"<\/a><\/figure>\n\n\n\n

\u30ab\u30ca\u30dc\u30a6\u30ce\u30ad\u5c5e Didierea<\/em> \u306b\u7279\u5fb4\u7684\u306a\u5f37\u976d\u306a\u523a\u306f\u3001\u8868\u76ae\u7d30\u80de\u3068\u8868\u76ae\u4e0b\u7d30\u80de\u304c\u786c\u5316\u3059\u308b\u3053\u3068\u3067\u5f62\u6210\u3055\u308c\u308b (Rauh 1956)\u3002\u786c\u5316\u3057\u305f\u5916\u5c64\u3092\u53d6\u308a\u9664\u304f\u3068\u3001\u523a\u306f\u9798\u72b6\u306e\u69cb\u9020\u3092\u3057\u3066\u3044\u308b\u3053\u3068\u304c\u308f\u304b\u308b\u3002\u305d\u306e\u5185\u5074\u306b\u306f\u7dd1\u8272\u306e\u76ae\u5c64\u304c\u3042\u308a\u3001\u786c\u5316\u5c64\u3092\u900f\u904e\u3057\u305f\u5149\u3092\u5229\u7528\u3057\u3066\u5149\u5408\u6210\u3092\u884c\u3063\u3066\u3044\u308b\u53ef\u80fd\u6027\u304c\u3042\u308b\u3002 <\/p>\n\n\n\n

The robust spines characteristic of the genus Didierea<\/em> are formed by the hardening of epidermal and subepidermal cells (Rauh 1956). When the hardened outer layer is removed, the spine is seen to have a sheath-like structure. Inside this layer is a green cortex, which may carry out photosynthesis using light transmitted through the hardened layer.<\/p>\n\n\n\n

\"\"<\/a><\/figure>\n\n\n\n

\u30ab\u30ca\u30dc\u30a6\u30ce\u30ad Didierea madagascariensis<\/em> \u306e\u9577\u679d\u306e\u5148\u7aef\u4ed8\u8fd1\u3092\u5207\u65ad\u3059\u308b\u3068 (\u5de6\u56f3\u306e\u8d64\u8272\u70b9\u7dda)\u3001\u5916\u5074\u304b\u3089\u3001\u786c\u5316\u3057\u305f\u8868\u5c64\u7d44\u7e54\u3001\u7dd1\u8272\u306e\u76ae\u5c64\u3001\u3084\u3084\u6728\u8cea\u5316\u3057\u305f\u6728\u90e8\u3092\u542b\u3080\u7dad\u7ba1\u675f\u7d44\u7e54\u3001\u305d\u3057\u3066\u830e\u306e\u5927\u90e8\u5206\u3092\u5360\u3081\u308b\u9ac4\u304b\u3089\u306a\u308b\u3053\u3068\u304c\u308f\u304b\u308b\u3002\u830e\u306e\u5185\u90e8\u306b\u306f\u6a39\u8102\u7d44\u7e54 (\u9ed2\u8272\u77e2\u5370) \u304c\u3042\u308a\u3001\u5207\u65ad\u3059\u308b\u3068\u7c98\u6027\u306e\u3042\u308b\u900f\u660e\u306a\u6db2\u4f53\u304c\u6ef2\u307f\u51fa\u3059\u3002 <\/p>\n\n\n\n

When a long shoot of Didierea madagascariensis<\/em> is cut near its apex (red dashed line in the left figure), it can be seen to consist, from the outside inward, of a hardened superficial tissue, a green cortex, vascular tissue containing slightly lignified xylem, and a pith that occupies most of the stem. Resinous tissue is present inside the stem (black arrow), and when the stem is cut, a viscous, transparent liquid exudes from it.<\/p>\n\n\n\n

\"\"<\/a><\/figure>\n\n\n\n

\u830e\u306e\u5148\u7aef\u304b\u3089\u7d041 m\u57fa\u90e8\u5074\u3092\u5207\u65ad\u3059\u308b\u3068 (\u5de6\u5199\u771f\u306e\u8d64\u8272\u5b9f\u7dda)\u3001\u9ac4\u306b\u306f\u306f\u3057\u3054\u72b6\u306e\u9699\u9593\u304c\u8a8d\u3081\u3089\u308c\u308b\u3002\u5148\u7aef\u4ed8\u8fd1\u3067\u306f\u3053\u306e\u3088\u3046\u306a\u9699\u9593\u306f\u8a8d\u3081\u3089\u308c\u306a\u3044\u305f\u3081\u3001\u6210\u9577\u904e\u7a0b\u3067\u5f62\u6210\u3055\u308c\u308b\u3068\u8003\u3048\u3089\u308c\u308b\u3002\u9699\u9593\u306e\u8868\u9762\u306f\u5e73\u6ed1\u3067\u3001\u8336\u8272\u306e\u7d30\u80de\u58c1\u3092\u3082\u3064\u7d30\u80de\u304c\u70b9\u5728\u3057\u3066\u3044\u308b\u304c\u3001\u305d\u306e\u5f62\u6210\u904e\u7a0b\u306f\u660e\u3089\u304b\u306b\u3055\u308c\u3066\u3044\u306a\u3044\u3002\u9ac4\u306f\u6c34\u5206\u8caf\u8535\u7d44\u7e54\u3068\u3057\u3066\u6a5f\u80fd\u3059\u308b\u3068\u8003\u3048\u3089\u308c\u3066\u304a\u308a\u3001\u4e7e\u5b63\u306b\u306f\u9ac4\u304b\u3089\u76ae\u5c64\u3084\u830e\u9802\u3078\u6c34\u5206\u304c\u4f9b\u7d66\u3055\u308c\u308b\u3068\u8003\u3048\u3089\u308c\u308b\u3002\u305d\u306e\u969b\u3001\u9ac4\u306b\u5207\u308c\u76ee\u304c\u3042\u308b\u3053\u3068\u3067\u3001\u6c34\u5206\u306e\u6e1b\u5c11\u306b\u4f34\u3063\u3066\u7d44\u7e54\u304c\u53ce\u7e2e\u3057\u3066\u3082\u3001\u7d44\u7e54\u5168\u4f53\u304c\u65ad\u88c2\u3059\u308b\u3053\u3068\u3092\u9632\u3044\u3067\u3044\u308b\u306e\u304b\u3082\u3057\u308c\u306a\u3044\u3002 <\/p>\n\n\n\n

When the stem is cut about 1 m below the apex (red solid line in the left photograph), ladder-like spaces are observed in the pith. Because such spaces are not observed near the apex, they are thought to form during the course of growth. The surfaces of the spaces are smooth, and cells with brown cell walls are scattered on them, but the process by which these spaces form remains unclear. The pith is thought to function as a water-storage tissue, and during the dry season, water is presumably supplied from the pith to the cortex and the shoot apex. The presence of breaks in the pith may prevent the entire tissue from rupturing as the tissue contracts in response to water loss.<\/p>\n\n\n\n

\"\"<\/a><\/figure>\n\n\n\n

\u9577\u679d\u3092\u5207\u65ad\u3057\u305f\u5f8c\u3001\u5207\u65ad\u9762 (\u5de6\u5199\u771f\u3001\u8d64\u8272\u5b9f\u7dda) \u306b\u9732\u51fa\u3057\u305f\u9ac4\u306f\u7d042\u9031\u9593\u3067\u4e7e\u71e5\u3057\u305f (\u4e2d\u592e\u5199\u771f)\u3002\u4e00\u65b9\u3001\u5207\u65ad\u5f8c\u7d042\u304b\u6708\u534a\u304c\u7d4c\u904e\u3057\u3066\u304b\u3089\u9577\u679d\u306e\u5148\u7aef\u90e8\u3092\u518d\u5ea6\u5207\u65ad\u3059\u308b\u3068 (\u5de6\u5199\u771f\u3001\u8d64\u8272\u70b9\u7dda)\u3001\u5185\u90e8\u306f\u306a\u304a\u6c34\u5206\u3092\u4fdd\u6301\u3057\u3066\u3044\u305f\u3002\u3053\u306e\u3053\u3068\u304b\u3089\u3001\u830e\u306f\u9ad8\u3044\u6c34\u5206\u4fdd\u6301\u80fd\u529b\u3092\u3082\u3064\u3068\u8003\u3048\u3089\u308c\u308b\u3002 <\/p>\n\n\n\n

After the long shoot was cut, the pith exposed on the cut surface (left photograph, red solid line) dried out in about two weeks (middle photograph). By contrast, when the apical part of the long shoot was cut again about two and a half months after the initial cut (left photograph, red dashed line), the interior still retained water. This suggests that the stem has a high capacity for water retention.<\/p>\n\n\n\n

\"\"<\/a><\/figure>\n\n\n\n

\u76ae\u5c64\u3084\u9ac4\u306b\u306f\u3001\u900f\u660e\u306b\u898b\u3048\u308b\u5206\u6ccc\u7d44\u7e54 (\u9ed2\u8272\u77e2\u5370) \u304c\u6563\u5728\u3059\u308b\u3002\u5206\u6ccc\u7269\u306f\u7c98\u6027\u3092\u3082\u3061\u3001\u50b7\u5bb3\u6642\u306b\u50b7\u53e3\u306e\u4fdd\u8b77\u306b\u95a2\u4e0e\u3057\u3066\u3044\u308b\u53ef\u80fd\u6027\u304c\u3042\u308b\u3002 <\/p>\n\n\n\n

Secretory tissues that appear transparent (black arrows) are scattered in the cortex and pith. The secretion is viscous and may be involved in protecting wounds after injury.<\/p>\n\n\n\n

\"\"<\/a><\/figure>\n\n\n\n

\u9ac4\u306b\u9699\u9593\u304c\u307e\u3060\u5f62\u6210\u3055\u308c\u3066\u3044\u306a\u3044\u830e\u306e\u5148\u7aef\u90e8\u3092\u5207\u65ad\u3059\u308b\u3068 (\u5de6\u4e0a\u5199\u771f)\u3001\u5207\u308a\u53e3\u306e\u7d44\u7e54\u304c\u5909\u5316\u3057\u3001\u8910\u8272\u3067\u4e7e\u71e5\u3057\u305f\u786c\u3044\u819c\u72b6\u306e\u67af\u6b7b\u7d44\u7e54\u304c\u5f62\u6210\u3055\u308c\u308b (\u53f3\u4e0a\u5199\u771f\u3002\u5de6\u4e0a\u5199\u771f\u3068\u306f\u5225\u306e\u5207\u65ad\u9762\u3092\u793a\u3059)\u3002\u3053\u306e\u67af\u6b7b\u7d44\u7e54\u306b\u3088\u308a\u3001\u5185\u5074\u306e\u7d44\u7e54\u306f\u4e7e\u71e5\u304b\u3089\u4fdd\u8b77\u3055\u308c\u3066\u3044\u308b\u3068\u8003\u3048\u3089\u308c\u308b (\u5de6\u4e0b\u5199\u771f)\u3002\u9ac4\u306b\u9699\u9593\u304c\u3042\u308b\u90e8\u5206\u3067\u5207\u65ad\u3057\u305f\u5834\u5408\u306b\u3082\u3001\u540c\u69d8\u306e\u67af\u6b7b\u7d44\u7e54\u304c\u5f62\u6210\u3055\u308c\u3001\u5185\u90e8\u3092\u4fdd\u8b77\u3057\u3066\u3044\u308b (\u53f3\u4e0b\u5199\u771f\u3002\u67af\u6b7b\u7d44\u7e54\u3092\u53d6\u308a\u9664\u304d\u5185\u5074\u3092\u793a\u3057\u305f\u3082\u306e)\u3002<\/p>\n\n\n\n

When the apical part of a stem in which spaces have not yet formed in the pith is cut (upper left photograph), the tissue at the cut surface changes and forms a brown, dry, hard, membrane-like necrotic tissue (upper right photograph, showing a different cut surface from that in the upper left photograph). This necrotic tissue is thought to protect the inner tissues from desiccation (lower left photograph). When the stem is cut in a region where spaces are present in the pith, similar necrotic tissue is also formed and protects the interior (lower right photograph, showing the inside after the necrotic tissue was removed).<\/p>\n\n\n\n

\"\"<\/a>
\u30ab\u30ca\u30dc\u30a6\u30ce\u30ad\u5c5e Didierea<\/em> \u2013 3. \u82b1\u5e8f\u3068\u82b1\u00a0 Didierea <\/em>\u2013 3. Inflorescences and Flowers<\/strong>
Didierea madagascariensis<\/em>_2: cropped a photo by avocat, https:\/\/www.inaturalist.org\/photos\/297193648, CC BY
Didierea trollii<\/em>_2: cropped a photo by CORDENOS Thierry, https:\/\/www.inaturalist.org\/photos\/77696178, CC BY-NC
Rauh, W. (1963). 121 Famille. Didiereacees. In Flore de Madagascar et des Comores: plantes vasculaires, , H. Humbert and J.-F. Leroy, eds. (Museum National D\u2019Histoire Naturelle), CC BY-NC-SA 4.0<\/figcaption><\/figure>\n\n\n\n
\"\"<\/a>
Didierea madagascariensis<\/em>_3: cropped a photo by Rob C. H. M. Oudejans, https:\/\/www.inaturalist.org\/photos\/58432374, CC BY-NC
Didierea trollii<\/em>_3: cropped a photo by dennis-mada, https:\/\/www.inaturalist.org\/photos\/4727865, CC BY-NC<\/figcaption><\/figure>\n\n\n\n

\u30ab\u30ca\u30dc\u30a6\u30ce\u30ad<\/strong>\u5c5e<\/strong> <\/strong>Didierea<\/em><\/strong> \u2013 3. <\/strong>\u82b1\u5e8f\u3068\u82b1<\/strong>  <\/strong>Didierea <\/em><\/strong>\u2013 3. Inflorescences and Flowers<\/strong><\/p>\n\n\n\n

\u30ab\u30ca\u30dc\u30a6\u30ce\u30ad\u5c5e\u306e\u82b1\u306f\u3001\u77ed\u679d\u306e\u9802\u7aef\u306b\u675f\u751f\u3059\u308b\u3002<\/p>\n\n\n\n

The flowers of the genus Didierea<\/em> are borne in clusters at the apices of short shoots.<\/p>\n\n\n\n

\"\"<\/a>
Didierea madagascariensis<\/em>_4: cropped a photo by Rob C. H. M. Oudejans, https:\/\/www.inaturalist.org\/photos\/58231286, CC BY-NC
Didierea trollii<\/em>_4: cropped a photo by dennis-mada, https:\/\/www.inaturalist.org\/photos\/4727865, CC BY-NC
Rauh, W. (1963). 121 Famille. Didiereacees. In Flore de Madagascar et des Comores: plantes vasculaires, , H. Humbert and J.-F. Leroy, eds. (Museum National D\u2019Histoire Naturelle). CC BY-NC-SA 4.0<\/figcaption><\/figure>\n\n\n\n

\u30ab\u30ca\u30dc\u30a6\u30ce\u30ad\u5c5e Didierea<\/em> \u306e\u82b1\u306f\u3001\u4ed6\u306e\u30ab\u30ca\u30dc\u30a6\u30ce\u30ad\u4e9c\u79d1\u306e\u7a2e\u3068\u540c\u69d8\u306b\u3001\u5bfe\u751f\u3059\u308b2\u679a\u306e\u82de\u8449\u30012\u679a\u306e\u5916\u82b1\u88ab\u7247\u30682\u679a\u306e\u5185\u82b1\u88ab\u7247\u30018\u672c\u7a0b\u5ea6\u306e\u96c4\u305a\u3044\u3001\u304a\u3088\u30731\u672c\u306e\u96cc\u305a\u3044\u3092\u5f62\u6210\u3059\u308b (Rauh 1963)\u3002\u96c4\u82b1\u3067\u306f\u96cc\u305a\u3044\u304c\u3001\u96cc\u82b1\u3067\u306f\u96c4\u305a\u3044\u304c\u5f62\u6210\u3055\u308c\u308b\u304c\u3001\u3044\u305a\u308c\u3082\u6210\u719f\u3057\u306a\u3044 (Rauh 1963)\u3002 <\/p>\n\n\n\n

The flowers of the genus Didierea<\/em>, as in other species of Didiereoideae, form two opposite bracts, two outer and two inner perianth segments, about eight stamens, and a single pistil (Rauh 1963). In male flowers, the pistil is formed but does not mature, whereas in female flowers, the stamens are formed but do not mature (Rauh 1963).<\/p>\n\n\n\n

\"\"<\/a>
\u30a2\u30eb\u30a2\u30a6\u30c7\u30a3\u30a2\u5c5e Alluaudia<\/em> \u306e\u7279\u5fb4\u00a0 Characteristics of the genus Alluaudia<\/em><\/strong><\/figcaption><\/figure>\n\n\n\n

\u30a2\u30eb\u30a2\u30a6\u30c7\u30a3<\/strong>\u30a2<\/strong>\u5c5e<\/strong> <\/strong>Alluaudia<\/em><\/strong> <\/strong>\u306e\u7279\u5fb4<\/strong>  <\/strong>Characteristics of the genus <\/strong>Alluaudi<\/em><\/strong>a<\/em><\/strong><\/p>\n\n\n\n

\u30a2\u30eb\u30a2\u30a6\u30c7\u30a3\u30a2\u5c5e Alluaudia<\/em> \u306f\u3001\u9577\u679d\u306e\u8449\u814b\u306b\u751f\u3058\u308b\u814b\u82bd\u306b\u304a\u3044\u3066\u3001\u5411\u8ef8\u5074\u3001\u3059\u306a\u308f\u3061\u9577\u679d\u306e\u5148\u7aef\u5074\u306b\u4f4d\u7f6e\u3059\u308b1\u679a\u306e\u521d\u671f\u8449\u304c\u523a\u5316\u3059\u308b\u3053\u3068\u3092\u7279\u5fb4\u3068\u3059\u308b\u3002\u307e\u305f\u3001Alluaudia dumosa<\/em> \u4ee5\u5916\u306e\u7a2e\u3067\u306f\u3001\u77ed\u679d\u306b\u5bfe\u751f\u3059\u308b2\u679a\u306e\u8089\u8cea\u8449\u3092\u5f62\u6210\u3059\u308b\u3002 <\/p>\n\n\n\n

The genus Alluaudia<\/em> is characterized by the modification into a spine of a single early leaf located on the adaxial side, that is, toward the apex of the long shoot, in the axillary bud formed in the axil of a long-shoot leaf. In species other than Alluaudia dumosa<\/em>, two opposite succulent leaves are formed on the short shoots.<\/p>\n\n\n\n

\"\"<\/a>
\u30a2\u30eb\u30a2\u30a6\u30c7\u30a3\u30a2\u5c5e Alluaudia<\/em> \u2013 1. \u8349\u59ff\u00a0 Alluaudia <\/em>\u2013 1. Habit<\/strong>
Alluaudia comosa<\/em>_1: cropped a photo by Laurence Ramon, https:\/\/www.inaturalist.org\/511786677,\u00a0 CC BY-NC<\/figcaption><\/figure>\n\n\n\n

\u30a2\u30eb\u30a2\u30a6\u30c7\u30a3<\/strong>\u30a2<\/strong>\u5c5e<\/strong> <\/strong>Alluaudia<\/em><\/strong> \u2013 1. <\/strong>\u8349\u59ff<\/strong>  <\/strong>Alluaudia <\/em><\/strong>\u2013 1. Habit<\/strong><\/p>\n\n\n\n

\u30a2\u30eb\u30a2\u30a6\u30c7\u30a3\u30a2\u5c5e Alluaudia<\/em> \u306f\u3001\u30de\u30c0\u30ac\u30b9\u30ab\u30eb\u5357\u90e8\u306b\u81ea\u751f\u3059\u308b6\u7a2e\u304b\u3089\u306a\u308b (POWO, GBIF.org, accessed 13 July 2026)\u3002\u9ad8\u30555 m\u7a0b\u5ea6\u306e\u704c\u6728\u72b6\u307e\u305f\u306f\u4f4e\u6728\u72b6\u306e\u7a2e\u304b\u3089\u3001\u9ad8\u305510 m\u307b\u3069\u306e\u9ad8\u6728\u72b6\u306b\u306a\u308b\u7a2e\u307e\u3067\u542b\u3080 (Rauh 1963)\u3002Alluaudia dumosa<\/em> \u3092\u9664\u304d\u3001\u77ed\u679d\u306b\u5bfe\u751f\u3059\u308b2\u679a\u7a0b\u5ea6\u306e\u8449\u3092\u3064\u3051\u308b\u3053\u3068\u3092\u7279\u5fb4\u3068\u3059\u308b (\u5de6\u4e0a\u5199\u771f)\u3002<\/p>\n\n\n\n

The genus Alluaudia<\/em> comprises six species native to southern Madagascar (POWO, GBIF.org, accessed 13 July 2026). It includes bushy or shrubby species reaching about 5 m in height, as well as tree-like species reaching about 10 m (Rauh 1963). With the exception of Alluaudia dumosa<\/em>, the genus is characterized by the formation of about two opposite leaves on the short shoots (upper left photograph).<\/p>\n\n\n\n

\"\"<\/a><\/figure>\n\n\n\n
\"\"<\/a>
\u30a2\u30eb\u30a2\u30a6\u30c7\u30a3\u30a2\u5c5e Alluaudia<\/em> \u2013 2. \u830e\u8449\u00a0 Alluaudia <\/em>\u2013 2. Stems and Leaves<\/strong><\/figcaption><\/figure>\n\n\n\n

\u30a2\u30eb\u30a2\u30a6\u30c7\u30a3<\/strong>\u30a2<\/strong>\u5c5e<\/strong> <\/strong>Alluaudia<\/em><\/strong> \u2013 2. <\/strong>\u830e\u8449<\/strong>  <\/strong>Alluaudia <\/em><\/strong>\u2013 2. Stems and Leaves<\/strong><\/p>\n\n\n\n

\u30a2\u30eb\u30a2\u30a6\u30c7\u30a3\u30a2\u5c5e Alluaudia<\/em> \u306e\u7a2e\u3067\u306f\u3001\u9577\u679d\u306b\u3064\u304f\u8089\u8cea\u8449\uff08\u767d\u8272\u77e2\u5370\uff09\u306e\u814b\u82bd\u304c\u77ed\u679d\u3068\u306a\u308b\u3002\u3053\u306e\u77ed\u679d\u3067\u306f\u3001\u5411\u8ef8\u5074\u3001\u3059\u306a\u308f\u3061\u9577\u679d\u306e\u5148\u7aef\u5074\u306b\u4f4d\u7f6e\u3059\u308b1\u679a\u306e\u521d\u671f\u8449\u304c\u523a\uff08\u9752\u8272\u77e2\u5370\uff09\u3078\u3068\u5909\u5f62\u3059\u308b\u3002\u9577\u679d\u306e\u830e\u9802\u4ed8\u8fd1\u3067\u306f\u3001\u77ed\u679d\u306e\u830e\u9802\u5206\u88c2\u7d44\u7e54\u306f\u7d44\u7e54\u306b\u57cb\u3082\u308c\u3066\u5916\u90e8\u304b\u3089\u306f\u898b\u3048\u305a\u3001\u9577\u679d\u306e\u8089\u8cea\u8449\u306e\u8449\u814b\u304b\u3089\u76f4\u63a5\u523a\u304c\u751f\u3058\u3066\u3044\u308b\u3088\u3046\u306b\u898b\u3048\u308b\uff08\u4e0a\u4e2d\u592e\u5199\u771f\uff09\u3002\u9577\u679d\u304c\u6210\u9577\u3059\u308b\u306b\u3064\u308c\u3066\u3001\u4ecb\u5728\u5206\u88c2\u306b\u3088\u308a\u9577\u679d\u306e\u8089\u8cea\u8449\u3068\u523a\u306e\u9593\u306e\u7d44\u7e54\u304c\u4f38\u9577\u3057\uff08\u9ed2\u8272\u4e21\u77e2\u5370\uff09\u3001\u4e21\u8005\u304c\u96e2\u308c\u308b\u3068\u77ed\u679d\u306e\u830e\u9802\uff08\u8d64\u8272\u77e2\u5370\uff09\u304c\u898b\u3048\u308b\u3088\u3046\u306b\u306a\u308b\uff08\u53f3\u4e0a\u5199\u771f\uff09\u3002\u3055\u3089\u306b\u9577\u679d\u304c\u6210\u9577\u3059\u308b\u3068\u3001\u77ed\u679d\u306e\u830e\u9802\u304b\u3089\u5bfe\u751f\u3059\u308b2\u679a\u306e\u8089\u8cea\u8449\uff08\u6a59\u8272\u77e2\u5370\uff09\u304c\u5f62\u6210\u3055\u308c\u308b\u3002<\/p>\n\n\n\n

In species of Alluaudia<\/em>, the axillary buds of the succulent leaves on the long shoots (white arrow) develop into short shoots. In these short shoots, a single early leaf located on the adaxial side, that is, toward the apex of the long shoot, is modified into a spine (blue arrow). Near the shoot apex of the long shoot, the shoot apical meristem of the short shoot is embedded in the tissue and is not visible externally, making it appear as though the spine arises directly from the axil of the succulent leaf on the long shoot (upper middle photograph). As the long shoot grows, the tissue between the succulent leaf of the long shoot and the spine elongates through intercalary growth (black double-headed arrow), and when the two become separated, the apex of the short shoot (red arrow) becomes visible (upper right photograph). As the long shoot grows further, two opposite succulent leaves (orange arrow) are formed from the apex of the short shoot.<\/p>\n\n\n\n

\"\"<\/a><\/figure>\n\n\n\n

\u4e7e\u5b63\u306b\u306f\u9577\u679d\u304a\u3088\u3073\u77ed\u679d\u306e\u8089\u8cea\u8449\u304c\u843d\u8449\u3059\u308b\u304c\u3001\u7fcc\u5e74\u4ee5\u964d\u306b\u65b0\u305f\u306b\u5f62\u6210\u3055\u308c\u308b\u306e\u306f\u77ed\u679d\u306e\u8089\u8cea\u8449\u306e\u307f\u3067\u3042\u308b\u3002<\/p>\n\n\n\n

During the dry season, the succulent leaves of both long and short shoots fall, but from the following year onward, only the succulent leaves of the short shoots are newly formed.<\/p>\n\n\n\n

\"\"<\/a>
Rauh, W. (1983). The morphology and systematic position of the Didiereaceae of\u00a0 Madagascar. Bothalia 14<\/em>, 839\u2013843. https:\/\/doi.org\/10.4102\/ABC.V14I3\/4.1251. CC BY 4.0<\/figcaption><\/figure>\n\n\n\n

\u5de6\u306e\u5199\u771f\u306f\u3001\u5012\u308c\u305f Alluaudia procera<\/em> \u306e\u830e\u306e\u6a2a\u65ad\u9762\u3067\u3042\u308b\u3002\u6728\u90e8 (\u8336\u8272\u77e2\u5370) \u306e\u5185\u5074\u306b\u306f\u9ac4 (\u6c34\u8272\u4e21\u77e2\u5370) \u304c\u3001\u5916\u5074\u306b\u306f\u76ae\u5c64 (\u7dd1\u8272\u4e21\u77e2\u5370) \u304c\u4f4d\u7f6e\u3059\u308b\u3002\u53cc\u5b50\u8449\u690d\u7269\u306b\u304a\u3051\u308b\u4e00\u6b21\u80a5\u5927\u6210\u9577\u306f\u3001\u76ae\u5c64\u307e\u305f\u306f\u9ac4\u306e\u7d30\u80de\u5897\u6b96\u306b\u3088\u3063\u3066\u5f15\u304d\u8d77\u3053\u3055\u308c\u308b\u3068\u3055\u308c\u3066\u304a\u308a (Troll and Rauh 1950)\u3001\u30a2\u30eb\u30a2\u30a6\u30c7\u30a3\u30a2\u5c5e Alluaudia<\/em> \u3084\u30b5\u30dc\u30c6\u30f3\u79d1\u3067\u306f\u76ae\u5c64\u304c\u80a5\u5927\u6210\u9577\u3059\u308b\uff08\u53f3\u4e0a\u6a21\u5f0f\u56f3\u5de6\uff09\u306e\u306b\u5bfe\u3057\u3001\u30ab\u30ca\u30dc\u30a6\u30ce\u30ad\u5c5e Didierea<\/em> \u3067\u306f\u9ac4\u304c\u80a5\u5927\u6210\u9577\u3059\u308b (\u53f3\u4e0a\u6a21\u5f0f\u56f3\u53f3)\u00a0 (Rauh 1956)\u3002 <\/p>\n\n\n\n

The photograph on the left shows a transverse section of the stem of a fallen Alluaudia procera<\/em>. The pith (light blue double-headed arrow) is located inside the xylem (brown arrow), and the cortex (green double-headed arrow) is located outside it. Primary thickening growth in dicotyledons is thought to be caused by cell proliferation in either the cortex or the pith (Troll and Rauh 1950). In the genus Alluaudia<\/em> and the family Cactaceae, the cortex undergoes thickening growth (upper right schematic, left), whereas in the genus Didierea<\/em>, the pith undergoes thickening growth (upper right schematic, right) (Rauh 1956).<\/p>\n\n\n\n

\"\"<\/a>
\u30a2\u30eb\u30a2\u30a6\u30c7\u30a3\u30a2\u5c5e Alluaudia<\/em> \u2013 3. \u82b1\u5e8f\u3068\u82b1\u00a0 Alluaudia <\/em>\u2013 3. Inflorescences and Flowers<\/strong>
Alluaudia comosa<\/em>_2: cropped a photo by globalherping, https:\/\/www.inaturalist.org\/photos\/401384720, CC BY-NC
Alluaudia comosa<\/em>_3: cropped a photo by Louis Aureglia, https:\/\/www.inaturalist.org\/photos\/455583401, CC BY<\/figcaption><\/figure>\n\n\n\n

\u30a2\u30eb\u30a2\u30a6\u30c7\u30a3<\/strong>\u30a2<\/strong>\u5c5e<\/strong> <\/strong>Alluaudia<\/em><\/strong> \u2013 3. <\/strong>\u82b1\u5e8f\u3068\u82b1<\/strong>  <\/strong>Alluaudia <\/em><\/strong>\u2013 3. Inflorescences and Flowers<\/strong><\/p>\n\n\n\n

\u30a2\u30eb\u30a2\u30a6\u30c7\u30a3\u30a2\u5c5e Alluaudia<\/em> \u306e\u82b1\u306f\u3001\u4ed6\u306e\u30ab\u30ca\u30dc\u30a6\u30ce\u30ad\u4e9c\u79d1\u306e\u7a2e\u3068\u540c\u69d8\u306b\u3001\u5bfe\u751f\u3059\u308b2\u679a\u306e\u82de\u8449\u30012\u679a\u306e\u5916\u82b1\u88ab\u7247\u30682\u679a\u306e\u5185\u82b1\u88ab\u7247\u30018\u672c\u7a0b\u5ea6\u306e\u96c4\u305a\u3044\u3001\u304a\u3088\u30731\u672c\u306e\u96cc\u305a\u3044\u3092\u5f62\u6210\u3059\u308b (Rauh 1963)\u3002\u96c4\u82b1\u3067\u306f\u96cc\u305a\u3044\u304c\u3001\u96cc\u82b1\u3067\u306f\u96c4\u305a\u3044\u304c\u5f62\u6210\u3055\u308c\u308b\u304c\u3001\u3044\u305a\u308c\u3082\u6210\u719f\u3057\u306a\u3044 (Rauh 1963)\u3002<\/p>\n\n\n\n

The flowers of the genus Alluaudia<\/em>, as in other species of Didiereoideae, form two opposite bracts, two outer and two inner perianth segments, about eight stamens, and a single pistil (Rauh 1963). In male flowers, the pistil is formed but does not mature, whereas in female flowers, the stamens are formed but do not mature (Rauh 1963).<\/p>\n\n\n\n

Alluaudia<\/em> \u306e\u7a2e\u3078\u306e\u691c\u7d22\u8868 (<\/strong>Rauh 1963<\/strong>\u3092\u6539\u5909)
<\/strong>\u30a2\u30eb\u30a2\u30a6\u30c7\u30a3\u30a2\u5c5e Alluaudia<\/em> \u3067\u306f\u3001\u7a2e\u306b\u3088\u3063\u3066\u3001\u8349\u4e08\u3001\u679d\u5206\u304b\u308c\u306e\u7a0b\u5ea6\u3001\u77ed\u679d\u306b\u304a\u3051\u308b\u8089\u8cea\u8449\u306e\u6709\u7121\u3001\u82b1\u5e8f\u306e\u5f62\u614b\u3001\u304a\u3088\u3073\u96cc\u82b1\u306e\u82de\u8449\u306b\u5f62\u6210\u3055\u308c\u308b\u7ffc\u306e\u5f62\u614b\u304c\u7570\u306a\u308b\u3002<\/strong><\/p>\n\n\n\n

1. \u77ed\u679d\u306b\u8089\u8cea\u306e\u8449\u3092\u5f62\u6210\u3057\u306a\u3044\u3002\u3000\u2026\u2026 Alluaudia dumosa<\/em><\/strong><\/p>\n\n\n\n

1. \u77ed\u679d\u306b\u8089\u8cea\u306e\u8449\u3092\u5f62\u6210\u3059\u308b\u3002\u3000\u2026\u2026 2<\/p>\n\n\n\n

2. \u82b1\u5e8f\u8ef8\u306f\u767a\u9054\u305b\u305a\u3001\u82b1\u306f\u9577\u679d\u306e\u8449\u814b\u306b\u675f\u751f\u3059\u308b\u3002\u679c\u6642\u306b\u96cc\u82b1\u306e\u82de\u8449\u80cc\u9762\u306b\u7ffc\u304c\u767a\u9054\u3059\u308b\u3002\u6a39\u51a0\u306e\u9802\u90e8\u3067\u9577\u679d\u304c\u6d3b\u767a\u306b\u5206\u679d\u3057\u3001\u679d\u304c\u5bc6\u96c6\u3059\u308b\u3002\u3000\u2026\u2026 Alluaudia comosa<\/em><\/strong><\/p>\n\n\n\n

2. \u82b1\u5e8f\u8ef8\u306f\u767a\u9054\u3057\u3001\u82b1\u306f\u9577\u679d\u306e\u8449\u814b\u304b\u3089\u51fa\u308b\u623f\u72b6\u306e\u82b1\u5e8f\u306b\u4ed8\u304f\u3002\u679c\u6642\u306b\u96cc\u82b1\u306e\u82de\u8449\u80cc\u9762\u306b\u7ffc\u304c\u767a\u9054\u3057\u306a\u3044\u3002\u6a39\u51a0\u306e\u9802\u90e8\u3067\u9577\u679d\u306f\u305d\u308c\u307b\u3069\u6d3b\u767a\u306b\u306f\u5206\u679d\u3057\u306a\u3044\u3002\u2026\u2026 3<\/p>\n\n\n\n

3. \u82b1\u5e8f\u306f\u5927\u578b\u3067\u3001\u76f4\u5f8430 cm\u306b\u9054\u3057\u3001\u679d\u5148\u8fd1\u304f\u306b\u96c6\u6563\u82b1\u5e8f\u3068\u306a\u308b\u3002\u3000\u2026\u2026 4<\/p>\n\n\n\n

3. \u82b1\u5e8f\u306f\u3088\u308a\u5c0f\u578b\u3067\u3001\u9577\u3055\u304a\u3088\u3073\u5e45\u306f\u6700\u592715 cm\u3002\u9577\u679d\u306e\u4e0a\u90e8\u306b\u6bb5\u968e\u7684\u306b\u3064\u304f\u3002\u3000\u2026\u2026 5<\/p>\n\n\n\n

4. \u5e7c\u690d\u7269\u306f\u57fa\u90e8\u304b\u3089\u3088\u304f\u5206\u679d\u3059\u308b\u3002\u6210\u6728\u306e\u5074\u679d\u306f\u304b\u306a\u308a\u591a\u3044\u3002\u77ed\u679d\u306e\u8449\u306f\u5012\u5375\u5f62\u3067\u3001\u5148\u7aef\u306f\u4e38\u304f\u3001\u82e5\u3044\u6642\u671f\u306b\u306f\u6709\u6bdb\u3002\u3000\u2026\u2026 Alluaudia procera<\/em><\/strong><\/p>\n\n\n\n

4. \u5e7c\u690d\u7269\u306f\u57fa\u90e8\u304b\u3089\u5206\u679d\u3057\u306a\u3044\u3002\u6210\u6728\u306e\u5074\u679d\u306f\u5c11\u306a\u3044\u3002\u77ed\u679d\u306e\u8449\u306f\u5186\u5f62\u3067\u3001\u5148\u7aef\u306f\u5207\u308c\u8fbc\u3080\u3002\u7121\u6bdb\u3002\u3000\u2026\u2026 Alluaudia montagnacii<\/em><\/strong><\/p>\n\n\n\n

5. \u9ad8\u305512 m\u306b\u9054\u3059\u308b\u9ad8\u6728\u3067\u3001\u5e79\u306f\u592a\u304f\u3001\u5074\u679d\u306f\u76f4\u7acb\u3057\u5c11\u6570\u3002\u77ed\u679d\u306e\u8449\u306f\u5186\u5f62\u3067\u3001\u5148\u7aef\u306f\u5207\u308c\u8fbc\u3080\u3002\u96cc\u82b1\u306e\u82de\u8449\u306e\u7ffc\u306e\u5927\u304d\u3055\u306f\u3001\u4e21\u65b9\u306e\u82de\u8449\u3067\u307b\u307c\u540c\u3058\u3002\u3000\u2026\u2026 Alluaudia ascendens<\/em><\/strong><\/p>\n\n\n\n

5. \u9ad8\u30555 m\u306b\u9054\u3059\u308b\u4f4e\u6728\u307e\u305f\u306f\u5c0f\u9ad8\u6728\u3067\u3001\u5e79\u306f\u7d30\u304f\u3001\u5074\u679d\u306f\u591a\u6570\u3042\u308a\u3001\u7d30\u9577\u304f\u3001\u591a\u5c11\u958b\u51fa\u3059\u308b\u3002\u77ed\u679d\u306e\u8449\u306f\u5012\u5375\u5f62\u3067\u3001\u5148\u7aef\u306f\u4e38\u3044\u304b\u3001\u5207\u5f62\u307e\u305f\u306f\u308f\u305a\u304b\u306b\u51f9\u3080\u3002\u96cc\u82b1\u306e\u82de\u8449\u306e\u7ffc\u306e\u5927\u304d\u3055\u306f\u3001\u7247\u65b9\u306e\u82de\u8449\u304c\u4ed6\u65b9\u3088\u308a\u9855\u8457\u306b\u5927\u304d\u3044\u3002\u3000\u2026\u2026 Alluaudia humbertii<\/em><\/strong><\/p>\n\n\n\n

Key to the species of Alluaudia<\/em> (modified from Rauh 1963)<\/strong><\/p>\n\n\n\n

In the genus Alluaudia<\/em>, species differ in plant height, degree of branching, presence or absence of succulent leaves on short shoots, inflorescence morphology, and the morphology of the wings formed on the bracts of female flowers.<\/p>\n\n\n\n

1. Succulent leaves are not formed on the short shoots. \u2026\u2026 Alluaudia dumosa<\/em><\/p>\n\n\n\n

1. Succulent leaves are formed on the short shoots. \u2026\u2026 2<\/p>\n\n\n\n

2. The inflorescence axis is not developed, and the flowers are clustered in the axils of long-shoot leaves. In fruit, wings develop on the dorsal surface of the bracts of the female flowers. Long shoots branch actively at the top of the crown, where the branches are densely crowded. \u2026\u2026 Alluaudia comosa<\/em><\/p>\n\n\n\n

2. The inflorescence axis is developed, and the flowers are borne in racemose inflorescences arising from the axils of long-shoot leaves. In fruit, wings do not develop on the dorsal surface of the bracts of the female flowers. Long shoots do not branch as actively at the top of the crown. \u2026\u2026 3<\/p>\n\n\n\n

3. Inflorescences are large, reaching 30 cm in diameter, and form cymose clusters near the branch tips. \u2026\u2026 4<\/p>\n\n\n\n

3. Inflorescences are smaller, up to 15 cm in length and width, and are borne successively on the upper parts of long shoots. \u2026\u2026 5<\/p>\n\n\n\n

4. Juvenile plants branch profusely from the base. Adult plants have rather many lateral branches. Leaves on the short shoots are obovate, rounded at the apex, and hairy when young. \u2026\u2026 Alluaudia procera<\/em><\/p>\n\n\n\n

4. Juvenile plants do not branch from the base. Adult plants have few lateral branches. Leaves on the short shoots are circular, with a notched apex, and glabrous. \u2026\u2026 Alluaudia montagnacii<\/em><\/p>\n\n\n\n

5. Tree reaching 12 m in height, with a thick trunk and few, erect lateral branches. Leaves on the short shoots are circular, with a notched apex. In female flowers, the wings of the two bracts are almost equal in size. \u2026\u2026 Alluaudia ascendens<\/em><\/p>\n\n\n\n

5. Shrub or small tree reaching 5 m in height, with a slender trunk and numerous, elongated, somewhat spreading lateral branches. Leaves on the short shoots are obovate, with the apex rounded, truncate, or slightly emarginate. In female flowers, the wing of one bract is markedly larger than that of the other. \u2026\u2026 Alluaudia humbertii<\/em><\/p>\n\n\n\n

\"\"<\/a>
Alluaudia dumosa<\/em>_1: cropped a photo by James Bailey, https:\/\/www.inaturalist.org\/photos\/608673761, CC BY-NC
Alluaudia dumosa<\/em>_2: cropped a photo by Stephane Philizot, https:\/\/www.inaturalist.org\/photos\/28865282, CC BY-NC<\/figcaption><\/figure>\n\n\n\n
\"\"<\/a>
Alluaudia comosa<\/em>_4: cropped a photo by Laurence Ramon, https:\/\/www.inaturalist.org\/photos\/511785808, CC BY-NC
Alluaudia comosa<\/em>_5: cropped a photo by Norbert Hahn, https:\/\/www.inaturalist.org\/photos\/447263472, CC BY-NC
Alluaudia comosa<\/em>_6: cropped a photo by CORDENOS Thierry, https:\/\/www.inaturalist.org\/photos\/111983593, CC BY-NC<\/figcaption><\/figure>\n\n\n\n
\"\"<\/a>
Alluaudia procera<\/em>_1: cropped a photo by lstock81, https:\/\/www.inaturalist.org\/photos\/669013073, CC BY-NC<\/figcaption><\/figure>\n\n\n\n
\"\"<\/a><\/figure>\n\n\n\n
\"\"<\/a>
Alluaudia montagnacii<\/em>_1: cropped a photo by lallen, https:\/\/www.inaturalist.org\/photos\/31284971, CC Public domain
Alluaudia montagnacii<\/em>_2: cropped a photo by amantedarmanin, https:\/\/www.inaturalist.org\/photos\/656044045, CC BY
Alluaudia montagnacii<\/em>_3: cropped a photo by amantedarmanin, https:\/\/www.inaturalist.org\/photos\/656046572, CC BY
Alluaudia montagnacii<\/em>_4: cropped a photo by amantedarmanin, https:\/\/www.inaturalist.org\/photos\/654333728, CC BY<\/figcaption><\/figure>\n\n\n\n
\"\"<\/a>
Alluaudia ascendens<\/em>_1: cropped a photo by Louis Aureglia, https:\/\/www.inaturalist.org\/photos\/382453626, CC BY
Rauh, W. (1963). 121 Famille. Didiereacees. In Flore de Madagascar et des Comores: plantes vasculaires, , H. Humbert and J.-F. Leroy, eds. (Museum National D\u2019Histoire Naturelle). CC BY-NC-SA 4.0<\/figcaption><\/figure>\n\n\n\n
\"\"<\/a>
Alluaudia humbertii<\/em>_1: cropped a photo by James Bailey, https:\/\/www.inaturalist.org\/photos\/608670109, CC BY-NC
Alluaudia humbertii<\/em>_2: cropped a photo by globalherping, https:\/\/www.inaturalist.org\/photos\/401184181, CC BY-NC
Alluaudia humbertii<\/em>_3: cropped a photo by dennis-mada, https:\/\/www.inaturalist.org\/photos\/11926595, CC BY-NC
Rauh, W. (1963). 121 Famille. Didiereacees. In Flore de Madagascar et des Comores: plantes vasculaires, , H. Humbert and J.-F. Leroy, eds. (Museum National D\u2019Histoire Naturelle). CC BY-NC-SA 4.0<\/figcaption><\/figure>\n\n\n\n

\u8b1d\u8f9e Acknowledgement<\/strong><\/p>\n\n\n\n

\u672c\u7a3f\u57f7\u7b46\u306b\u3042\u305f\u308a\u3001\u540d\u53e4\u5c4b\u5e02\u6771\u5c71\u52d5\u690d\u7269\u5712\u306e\u30ab\u30ca\u30dc\u30a6\u30ce\u30ad\u306e\u683d\u57f9\u682a\u3092\u89b3\u5bdf\u3055\u305b\u3066\u3044\u305f\u3060\u3044\u305f\u3002\u5fc3\u3088\u308a\u611f\u8b1d\u7533\u3057\u4e0a\u3052\u307e\u3059\u3002<\/p>\n\n\n\n

\u5f15\u7528\u6587\u732e\u00a0 References<\/strong><\/p>\n\n\n\n

Bond, W.J., and Silander, J.A. (2007). Springs and wire plants: anachronistic defences against Madagascar\u2019s extinct elephant birds. Proceedings of the Royal Society B: Biological Sciences 274<\/em>, 1985\u20131992. https:\/\/doi.org\/10.1098\/RSPB.2007.0414.<\/p>\n\n\n\n

Bruyns, P. V., Oliveira-Neto, M., Melo-de-Pinna, G.F., and Klak, C. (2014). Phylogenetic relationships in the Didiereaceae with special reference to subfamily Portulacarioideae. Taxon 63<\/em>, 1053\u20131064. https:\/\/doi.org\/10.12705\/635.36<\/a>.<\/p>\n\n\n\n

Carolin, R.C. (1993). Portulacaceae. In The Families and Genera of Vascular Plants. Volume II. Magnoliid, Hamamelid and Caryophyllid Families, K. Kubitzki, J. G. Rohwer, and V. Bittrich, eds. (Springer), pp. 544\u2013555.<\/p>\n\n\n\n

Choob, V. (2022). Prophyll in Monocots: The Starting Point of Lateral Shoot Phyllotaxis. Front. Plant Sci. 13<\/em>, 855146. https:\/\/doi.org\/10.3389\/FPLS.2022.855146\/TEXT.<\/p>\n\n\n\n

Crowley, B.E., and Godfrey, L.R. (2011). A glance to the past: subfossils, stable isotopes, seed dispersal, and lemur species loss in Southern Madagascar. Am. J. Primatol. 73<\/em>, 25\u201337. https:\/\/doi.org\/10.1002\/AJP.20817.<\/p>\n\n\n\n

Erbar, C., and Leins, P. (2006). Floral ontogeny and systematic position of the Didiereaceae. Plant Syst. Evol. 261<\/em>, 165\u2013185.<\/p>\n\n\n\n

Kubitzki, K. (1993). Didiereaceae. In The Families and Genera of Vascular Plants. Volume II. Magnoliid, Hamamelid and Caryophyllid Families, K. Kubitzki, J. G. Rohwer, and V. Bittrich, eds. (Springer), pp. 292\u2013295.<\/p>\n\n\n\n

Marloth, R. (1913). The Flora of South Africa, Volume I (Darter Bros. & Co.).<\/p>\n\n\n\n

Ocampo, G., and Columbus, J.T. (2010). Molecular phylogenetics of suborder Cactineae (Caryophyllales), including insights into photosynthetic diversification and historical biogeography. Am. J. Bot. 97<\/em>, 1827\u20131847. https:\/\/doi.org\/10.3732\/AJB.1000227;SUBPAGE:STRING:FULL.<\/p>\n\n\n\n

Pax, F. and Hoffmann, K. 1936. Capparidaceae. In: Engler, A. & Prantl, K. (eds.), Die nat\u00fcrlichen Pflanzenfamilien<\/em>, 2nd ed., Band 17b: 146\u2013223. Leipzig: Wilhelm Engelmann.<\/p>\n\n\n\n

Pearson, H.H.W., and Stephens, L. (1912). List of the plants collected in the Percy Sladen Memorial Expedition, 1908-1909, 1910-1911: Portulacaceae. Ann. South African Museum 9<\/em>, 30\u201335.<\/p>\n\n\n\n

POWO (2026). Plants of the World Online<\/em>. Facilitated by the Royal Botanic Gardens, Kew. Published on the Internet; https:\/\/powo.science.kew.org\/<\/a>. Retrieved 7 July 2026.<\/p>\n\n\n\n

Rauh, W. (1956). Morphologische, entwicklungsgeschichtliche, histogenetische und anatomische Untersuchungen an den Sprossen der Didiereaceen. Abhandlungen der Akademie der Wissenschaften und der Literatur, Mathematisch-Naturwissenschaftliche Klasse 1956 (6)<\/em>, 369\u2013540.<\/p>\n\n\n\n

Rauh, W. (1960\/1961). Weitere Untersuchungen an Didiereaceen. 1. Teil: Beitrag zur Kenntnis der Wuchsformen der Didiereaceen, unter besonderer Ber\u00fccksichtigung neuer Arten. Sitzungsberichte der Heidelberger Akademie der Wissenschaften, Mathematisch-Naturwissenschaftliche Klasse, Jahrgang 1960\/1961, 185\u2013300.<\/p>\n\n\n\n

Rauh, W. (1963). 121 Famille. Didiereacees. In Flore de Madagascar et des Comores: plantes vasculaires, , H. Humbert and J.-F. Leroy, eds. (Museum National D\u2019Histoire Naturelle).<\/p>\n\n\n\n

Rauh, W. (1983). The morphology and systematic position of the Didiereaceae of  Madagascar. Bothalia 14<\/em>, 839\u2013843. https:\/\/doi.org\/10.4102\/ABC.V14I3\/4.1251. Troll, W., and Rauh, W. (1950). Das Erstarkungswachstum krautiger Dikotylen, mit besonderer Ber\u00fccksichtigung der prim\u00e4ren Verdickungsvorg\u00e4nge. Sitzungsber. Heidelb. Akad. Wiss. Math. Naturwiss. Kl. 1950<\/em>, 1\u201386.<\/p>\n","protected":false},"excerpt":{"rendered":"

\u30ab\u30ca\u30dc\u30a6\u30ce\u30ad\u79d1  Didiereaceae \u306f\u3001\u4e7e\u71e5\u5730\u306b\u9069\u5fdc\u3057\u305f\u591a\u8089\u6027 … \u7d9a\u304d\u3092\u8aad\u3080 →<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":[],"categories":[81,1],"tags":[],"_links":{"self":[{"href":"http:\/\/www.nibb.ac.jp\/plantdic\/blog\/index.php?rest_route=\/wp\/v2\/posts\/1611"}],"collection":[{"href":"http:\/\/www.nibb.ac.jp\/plantdic\/blog\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/www.nibb.ac.jp\/plantdic\/blog\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/www.nibb.ac.jp\/plantdic\/blog\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/www.nibb.ac.jp\/plantdic\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=1611"}],"version-history":[{"count":5,"href":"http:\/\/www.nibb.ac.jp\/plantdic\/blog\/index.php?rest_route=\/wp\/v2\/posts\/1611\/revisions"}],"predecessor-version":[{"id":1671,"href":"http:\/\/www.nibb.ac.jp\/plantdic\/blog\/index.php?rest_route=\/wp\/v2\/posts\/1611\/revisions\/1671"}],"wp:attachment":[{"href":"http:\/\/www.nibb.ac.jp\/plantdic\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=1611"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/www.nibb.ac.jp\/plantdic\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=1611"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/www.nibb.ac.jp\/plantdic\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=1611"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}