Japanese name: イラクサ（刺草、荊草、苛草、蕁草） Scientific name:Urtica thunbergiana
[Overview]
A perennial 40–80 cm tall, found in damp places in forests and at forest edges in the mountains.
The whole plant is covered with brittle, sharp stinging hairs, and it is famous for causing intense pain when touched.
The stems grow in clumps; they are cylindrical and densely covered with downward-pointing hairs.
Leaves are simple and opposite, ovate, 5–15 cm long and 4–10 cm wide, with a tail-like pointed tip.
The upper surface of the leaf is sparsely hairy, and the veins on the underside have short hairs.
The leaf margin has deeply notched teeth that are often doubly serrate.
The stipules are 7–8 mm long, fused together, oblong, and sometimes 2-lobed at the tip.
There are male flowers and female flowers.
Spike-like inflorescences emerge from the leaf axils, with female inflorescences on the upper part of the stem and male inflorescences on the lower part.
Both male and female flowers are small, pale green, and 4-petaled.
The fruit is a flattened achene about 1 mm long.
[Uses]
The whole plant is called jinma and is used medicinally, for example as a local irritant.
