Japanese name: カワラスガナ（川原菅菜、河原菅菜） Scientific name:Cyperus sanguinolentus
[Overview]
An annual 10–40 cm tall, found in damp places such as riverbanks and the edges of rice fields.
The base of the stem is ascending or lies sideways.
The stems are tufted and triangular in cross section.
The leaves are linear, 0.1–0.3 cm wide, and shorter than the stems.
Many spikelets are densely clustered in a head at the stem tip, with 2–3 long leaf-like bracts at the base.
The inflorescence sometimes bears short branches.
The spikelets are partly tinged blood red, flattened and oblong, about 1–2 cm long and 0.3 cm wide.
The fruit is about 0.1 cm long, broadly obovate and blackish brown.
