Hydrocotyle verticillata var. triradiata(whorled pennywort, "Uchiwazenikusa")
Japanese name: ウチワゼニクサ（団扇銭草） Scientific name:Hydrocotyle verticillata var. triradiata
[Overview]
A perennial growing in wetlands and marshes as well as other moist places, often forming colonies.
The whole plant is soft, and the stem branches, creeps along the ground, and spreads by producing roots from the nodes.
The leaves are alternate, round, 1–5 cm in diameter, with shallow notches and a glossy upper surface.
A petiole 3–20 cm long is attached to the center of the leaf in a peltate manner, and the veins radiate outward.
Umbels emerge on flower stalks from the leaf axils, bearing several flowers at a time in whorl-like arrangements.
The flowers are very small, pale green, star-shaped 5-petaled flowers with 5 stamens and 2 styles.
The fruit is a schizocarp with the styles remaining.
[History]
It was confirmed on Awaji Island, Hyogo, in 1987, and has been confirmed as naturalized mainly in warm regions.
