Adenostemma latifolium ("Okadaikon")

Japanese name: オカダイコン （丘大根）
Scientific name: Adenostemma latifolium

[Overview]
A perennial 0.3–1.5 m tall, growing in shaded places at woodland edges and roadsides.
It has thickened rhizomes.
The base of the stem creeps briefly along the ground and roots, while the upper part is erect.
The leaves are simple, in 8–12 opposite pairs, ovate to broadly ovate; those in the middle of the stem are 15–40 cm long including the petiole and 7–22 cm wide, with a petiole 5–10 cm long.
The leaf tip is sharply pointed, the base is rounded to truncate, and there are 20–30 pairs of high, pointed teeth.
White flower heads are borne several at a time in corymbs at the tips of long stalks, and each flower head has a short, hairy stalk.
Each flower head consists of about 30 florets, and the corolla is tubular, about 2 mm long, and shallowly 2-lobed.
The involucre is spherical, about 1 cm across, and the involucral bracts are arranged in 2 rows and joined at the base.
The fruit is an oblanceolate achene about 3.5 mm long, blackish brown and dull, with sparse glandular dots on the surface, but it does not become scab-like when dry.
The pappus is club-shaped, with 3–4 elements arranged radially, and secretes a sticky fluid.

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