Rock fleas - Rock fleas

It is a deciduous climbing woody plant of the Saxifragaceae family (APG classification: Hydrangeaceae), which grows aerial roots from the branches and clings to rocks and trunks to climb to high places. The leaves are long stalked and opposite, with broad ovate-cordate leaf blades that are sharply pointed at the tip and have sharp serrated edges. In June and July, it produces corymbs at the ends of the branches. Around the inflorescences are white ovate decorative flowers with one sepal that has developed into a petal shape, and in the center are many small bisexual flowers. The five petals of the bisexual flower do not open flat, but are cap-shaped with the tips still attached to each other, and it has ten stamens and one thick style that ends in a head-shaped stigma. The ovary is semi-inferior. It grows in mountainous areas and is widely distributed from Hokkaido to Kyushu.

[Michio Wakabayashi March 22, 2021]

Source: Shogakukan Encyclopedia Nipponica About Encyclopedia Nipponica Information | Legend

ユキノシタ科（APG分類：アジサイ科）の落葉つる性木本で、枝から気根を出し、岩や樹幹に絡みついて高所によじ登る。葉には長い柄があって対生し、葉身は広卵心形で先は鋭くとがり、縁(へり)に鋭鋸歯(えいきょし)がある。6～7月、枝の先に散房状集散花序をつくる。花序の周囲には、1枚の萼片(がくへん)が花弁状に発達した白色卵形の装飾花があり、中央には多数の小さな両性花をつける。両性花の5枚の花弁は平開せず、先端が互いにくっついたままで帽子状にとれ、雄しべは10本、花柱は1本で太く、頭状の柱頭に終わる。子房は半下位。山地に生え、北海道から九州まで広く分布する。

［若林三千男　2021年3月22日］

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