うらじろたで (裏白蓼)

Pleuropteropyrum weyrichii

Pleuropteropyrum weyrichii

Pleuropteropyrum weyrichii

Pleuropteropyrum weyrichii

Pleuropteropyrum weyrichii

Pleuropteropyrum weyrichii

Pleuropteropyrum weyrichii

Pleuropteropyrum weyrichii

Pleuropteropyrum weyrichii

Pleuropteropyrum weyrichii

Pleuropteropyrum weyrichii

Pleuropteropyrum weyrichii

Pleuropteropyrum weyrichii

Pleuropteropyrum weyrichii

Pleuropteropyrum weyrichii

Pleuropteropyrum weyrichii

Pleuropteropyrum weyrichii

Pleuropteropyrum weyrichii

Pleuropteropyrum weyrichii

Pleuropteropyrum weyrichii

Pleuropteropyrum weyrichii

Pleuropteropyrum weyrichii

Pleuropteropyrum weyrichii

Pleuropteropyrum weyrichii

Pleuropteropyrum weyrichii

Pleuropteropyrum weyrichii

Pleuropteropyrum weyrichii

Pleuropteropyrum weyrichii

わが国の本州、北アルプスの中北部から東北地方の八甲田山、北海道、南千島やサハリンに分布しています。高山帯の砂礫地や崩壊地に生え、高さは30〜100センチになります。雌雄異株です。茎は太くて曲がり、葉は卵形から長卵形で先は尖ります。裏面には白い綿毛が密生しています。6月から10月ごろ、黄白色の花を咲かせます。 
タデ科オンタデ属の多年草で、学名は Pleuropteropyrum weyrichii。
英名はありません。 
"Urajiro-tade" (Pleuropteropyrum weyrichii) belongs to the Polygonaceae (the Knotweed family). It is a perennial herb that is native from the north-central North Japan Alps north to Mt. Hakkouda in Tohoku district, Hokkaido the southern Kril Islands and the Sakhalin. This herb grows in alpine screes and landslide scars, and it can reach 30-100 cm in height. It is dioecious. The stems are thick, bending and the leaves are ovate to long-ovate with acute tips. The abaxial side of leaves are covered with dense white wooly hairs. The yellowish white flowers bloom from June to October. 
[上] 富山県宇奈月町黒部「鹿島槍ヶ岳」にて、
2002年07月21日撮影。(photo by Aya Suehiro)
[中1〜中9] 栃木県那須町「1900m峰」にて、
2014年08月13日撮影。
[中10〜中19] 栃木県那須町「茶臼岳」にて、
2014年08月14日撮影。
[中20〜26・下] 同上にて、2015年07月11日撮影。 

Shu Suehiro
shu@botanic.jp