はなこみかんぼく (花小蜜柑木) [Index] [Back] わが国の沖縄中部、恩納村の万座毛（まんざもう）近辺のみに見られる固有種です。海岸の岩場に生え、高さは２０〜４０センチになります。茎は分枝が多く、先端近くからは側方に伸びる落下枝を多数広げます。落下枝は長さ７〜１０センチで斜め上向きに伸び、直径は０．５ミリ程度で、小さな卵状楕円形から楕円形の葉を左右二列に、密に互生します。ほとんど一年中、落下枝の下の葉腋に、赤い小さな花を下垂して咲かせます。雌雄同株で、雄花は２〜３個が束生し萼片は４個、雌花は雄花より長い柄があり、萼片は６個あります。果実は扁球形の�刮ﾊです。環境省のレッドリストでは絶滅危惧ＩＢ類（ＥＮ）に指定されています。 ※落下枝（らっかし）は、植物学的には樹木が自身の維持・管理のために枝を能動的に切り離す現象で、「自然剪定」とも呼ばれます。 トウダイグサ科コミカンソウ属の落葉小低木で、学名は Phyllanthus liukiuensis。英名はありません。 The "Hana-komikanboku" (Phyllanthus liukiuensis) belongs to Euphorbiaceae (the Spurge family). It is a deciduous shrub that is an endemic species found exclusively in the vicinity of Manzamou in Onna Village, central Okinawa. It grows on coastal rocky outcrops and reaches a height of 20 to 40 cm. The stem is highly branched, and near the tip, it spreads out numerous lateral shedding branches. The shedding branches are 7-10 cm long and grow at an upward angle; they are about 0.5 mm in diameter and bear small, ovate-elliptical to elliptical leaves arranged in two dense, alternate rows on either side. Almost year-round, small red flowers hang downward from the leaf axils beneath the shedding branches. The plant is monoecious; male flowers grow in clusters of two to three with four sepals, while female flowers have longer pedicels than the male flowers and six sepals. The fruit is a flattened spherical capsule. It is designated as Endangered (EN) on the Ministry of the Environment’s Red List. *In botany, "cladoptosis" (branch shedding) refers to the phenomenon where a tree actively sheds branches for self-maintenance and management; it is also known as "natural pruning". 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