Bidens tripartita var. tripartita(three-lobe beggartick, "Taukogi")
Japanese name: タウコギ（田五加木） Scientific name:Bidens tripartita var. tripartita
[Overview]
An annual 0.2–1.5 m tall, found on paddy banks and in wetlands.
The stem is green, much branched, and usually hairless.
The leaves are opposite and 3–5-lobed with toothed lobes, but the leaves on the upper part of the stem are undivided simple leaves.
The petiole is slightly winged.
Yellow flower heads are borne facing upward at the tips of branches on the upper part of the stem.
The flower heads are 0.7–0.8 cm across at first, later becoming 2.5–3.5 cm across, and have no ray florets.
The outer involucral bracts are leaf-like, 1.5–4.5 cm long, and number 4–5.
The fruit is a flattened achene 0.7–1.1 cm long, with 2 awns (spines), rarely 3–4.
The awns, together with the margins of the achene and the midrib on its faces, have small downward-pointing barbs.
[Notes]
It grows in rice paddies, and the Japanese name derives from its leaves resembling those of Ukogi.
