Ludwigia octovalvis (Mexican primrose-willow, "Kidachikinbai")

Japanese name: キダチキンバイ （木立金梅）
Scientific name: Ludwigia octovalvis

[Overview]
A perennial 1–2 m tall, found in wetlands along rivers, at the edges of ponds and marshes, and in rice paddies.
The stems and leaves have coarse hairs.
The stem is erect and woody, ridged, and branches well, forming a shrub.
Leaves are simple and alternate, long lanceolate to linear, 3–10 cm long and 0.8–4 cm wide, with entire, hairy margins; the leaf base does not form wings (fins).
Flowers are solitary in the leaf axils and are yellow, 4-petaled, about 2–3 cm across.
The fruit is a capsule about 3–5 cm long, with 4 ridges, forming a square column, with the 4 sepals remaining at the top.

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