いそふじ (磯藤) [Index] [Back] わが国の奄美群島から先島群島、小笠原諸島、それに台湾や東南アジア、太平洋諸島に広く分布しています。海岸の砂浜や岩礁に生え、高さは１〜３メートルになります。幹は直立し、樹皮は黄褐色で皮目（ひもく）によって表面がざらついています。葉は奇数羽状複葉で、卵形の小葉が５〜８対つきます。８月から１２月ごろ、枝先の総状花序に、鮮やかに黄色い蝶形花を咲かせます。果実は数珠状の豆果で、長さ１０〜１５センチあり、長く枝に残って目立ちます。全草にリコリンなどのアルカロイド系の有毒成分を含んでいます。環境省のレットブックでは絶滅危惧ＩＢ類（ＥＮ）に指定されています。台湾華語では「毛苦參」、中国語では「絨毛槐（rong mao huai）」と呼ばれます。 マメ科クララ属の常緑低木で、学名は Sophora tomentosa。英名 Silver bush、Necklace pod、Downy sophora。 The Silver bush (Sophora tomentosa) belongs to Fabaceae (the Pea family). It is a small evergreen tree that is widely distributed from Japan's Amami Islands to the Sakishima Islands and the Ogasawara Islands, as well as in Taiwan, Southeast Asia, and the Pacific Islands. It grows on sandy beaches and rocky reefs along the coast and reaches a height of 1 to 3 m. The trunk is erect, and the bark is yellowish-brown with a rough surface due to lenticels. The leaves are odd-pinnate compound leaves with 5 to 8 pairs of ovate leaflets. From August to around December, bright yellow butterfly-shaped flowers bloom in racemes at the tips of the branches. The fruit is a bead-like pod, 10-15 cm long, which remains on the branches for a long time and is quite conspicuous. The entire plant contains toxic alkaloids such as lycorine. It is designated as Endangered (EN) in Category IB on the Ministry of the Environment's Red List. It is called "毛苦參" in Taiwanese Chinese and "絨毛槐" (rong mao huai) in Chinese. 茨城県つくば市「つくば実験植物園」にて、2026年03月28日撮影。 Shu Suehiro shu@botanic.jp