Japanese name: イガオナモミ（毬雄生揉、毬葈耳） Scientific name:Xanthium orientale subsp. italicum
[Overview]
An annual 0.5–1.5 m tall, found in grassland and on riverbanks, often growing in colonies.
The stem is erect and much branched, with blackish purple spots.
The stem has short hairs and is rough to the touch.
The leaves are alternate, broadly ovate, 6–9 cm long and 6–12 cm wide, and are usually shallowly 3-lobed (rarely 5-lobed).
The upper surface of the leaf has fine hairs, and the underside has short hairs and is rough.
The leaf margin has shallow, blunt teeth.
The leaf stalk is long, and there are no spines at the base of the leaf.
There are male and female flowers; the male flowers are yellowish white and borne in short cones at the stem tips and in the leaf axils, and the female flowers are pale green and borne singly or several together in the leaf axils below the male inflorescences.
The fruit is elliptic, with 2 horns at the tip, and is about 2–3 cm long and 1.2–2.2 cm wide including the horns.
The surface of the fruit is densely covered with spines whose tips are bent into hooks.
The fruit is covered with many hairs and glandular hairs.
[History]
It was first recorded in Tokyo in the 1950s and has since become naturalized in various places.
