Polygonum barbatum subsp. gracile Danser in Bull. Jard. B. Buitenzorg Ser. 3, 8: 146. f. 2. 1927; Polygonum barbatum var. gracile (Danser) Steward in Contr. Gray Herb. 88: 55. 1930; Persicaria barbata subsp. gracilis (Danser) Sojak in Preslia 46: 152. 1974; Polygonum serrulatum sensu Hook.f., Fl.Brit. Ind. 5: 38. 1886 non Lag. 1816 p.p.

Fl. Per.: Throughout the year.

Lectotype: Laora (West Soemba) 1925, Iboet 329 gezeichnet.

More frequent than the type variety, common from plains to almost 2000 m. Grows near water; Distribution: Similar to type variety.

This taxon is often confused with Persicaria satisifolia (Brouss. ex Willd.) Assenov - a mediterranean species which does not occur in our region. See discussion under excluded species.