Kyllinga monocephala Rottbøll var. leiolepis Franchet & Savatier, Enum. Pl. Jap. 2: 108. 1877; Cyperus brevifolius var. gracillimus (Miquel) Kükenthal; K. brevifolia var. leiocarpa Kitagawa; K. gracillima Miquel; K. monocephala var. leiocarpa Kitagawa.

Longest involucral bract oblique to horizontal. Spikelets slightly broad and turgid. Glumes not spinulose on keel, apex without a mucro or sometimes with a strict mucro. Fl. and fr. May-Oct.

Naturalized in E North America, this variety has a more northerly distribution than the others and has been treated as a species, Kyllinga gracillima, in some floras (e.g., Fl. N. Amer. 23: 193-194. 2002).

Along trails, grassland slopes, river margins, shallow water, wet places at seashores, paddy field margins; near sea level to 1200 m. Anhui, Fujian, Gansu, Hebei, Henan, Hubei, Jiangsu, Jilin, Liaoning, Shaanxi, Shandong, Shanxi, NW Yunnan, Zhejiang [Japan, Korea, Nepal, Russia (Far East)].