Japanese name: ミクリ（実栗） Scientific name:Sparganium erectum
[Overview]
A perennial 50–200 cm tall, growing in colonies in shallow water of ponds, marshes and wetlands.
The rhizome creeps horizontally and forms young plants at its tip.
The leaves are alternate in two rows, linear, 8–15 mm wide, with a ridge on the underside, so that the cross-section is triangular.
The leaf base forms a sheath.
The inflorescence is branched and bears spherical flower heads (capitula).
On the lower part of the inflorescence branch there are 1–3 stalkless female flower heads, and on the upper part there are many stalkless male flower heads.
The fruit is obovate, 6–9 mm long, and forms an aggregate fruit 1.5–2 cm in diameter.
The fruit is a nut; the outside of the pericarp is soft and spongy, and the inside is hard.
[Uses]
The rhizome is used medicinally.
The stems are dried and woven to make blinds of sanryo-so (三稜草).
[Notes]
The Japanese name compares the aggregate fruit to the burr of a chestnut.
