たちがしわ (立ち柏) [Index] [Back] わが国の固有種で、本州に分布しています。（四国や九州にも分布域があるとの記述もありますが、確認できないので省きます。）落葉樹林の木かげに生え、高さは３０〜６０センチになります。茎は直立し、分枝しないで、細かい毛が生えます。葉は広卵円形で、茎の先に集まってつきます。また葉は、花後、大きくなります。５月から６月ごろ、茎頂に緑褐色の花をやや密に咲かせます。花冠は深く５裂し、無毛です。果実は袋果で、２個が互いに斜上します。また秋にはその袋果が割れ、白い絹糸状の冠毛をつけた種子がはじけます。和名は「つるがしわ（蔓柏）」に似ていて、茎が直立することから。  ガガイモ科カモメヅル属の多年草で、学名は Cynanchum magnificum (syn. Vincetoxicum magnificum)。英名はありません。  "Tachi-gashiwa" (Cynanchum magnificum) belongs to Asclepiadaceae (the Milkweed family). It is a perennial herb that is endemic to Japan and is distributed in Honshu. (There are also reports that it has a distribution range in Shikoku and Kyushu, but we have not been able to confirm this, so we will omit those reports.) It grows in the shade of deciduous forests and is 30-60 cm tall. The stem is erect and unbranched, with fine hairs. The leaves are broadly ovate and clustered at the end of the stem. The greenish-brown flowers bloom rather densely at the top of the stem from May to June. The corolla has five deep lobes and is hairless. The fruit is a follicle, with the two fruits obliquely raised above each other. In fall, the follicles split open and the seeds, which are covered with white silky pappus, burst forth. The Japanese name is derived from its upright stem, which resembles the "Tsuru-gashiwa" (Vincetoxicum macrophyllum var. nikoense).  福島市松川町水原「水原地区くまがいそう自生地」にて、2023年05月04日撮影。  Shu Suehiro shu@botanic.jp