矮黑三棱 ai hei san leng

Sparganium minimum Wallroth.

Stems slightly prostate or rarely erect, to 20 cm, slender. Leaves aerial or floating, 20-25 cm × ca. 4 mm, flattened. Spikes or racemes 2-3.5 cm; male heads 1(or 2); female heads 2(or 3), lowest one sometimes pedunculate. Male flowers: perianth segments ca. 1.5 mm, lobate at apex; filaments ca. 2 mm; anthers oblong, ca. 1 mm. Female flowers: perianth segments spatulate, ca. 2 mm, lobate to parted at apex; ovary lanceolate, with or without short stalk; styles short; stigmas ca. 1 mm. Fruit broadly lanceolate. Fl. and fr. Jul-Sep. 2n = 30.

Below 3500 m. Heilongjiang, Nei Mongol, Sichuan [Kazakhstan, Mongolia, Russia; Europe, North America].

Specimens described as Sparganium amplexicaulium D. Yu (Bull. Bot. Res., Harbin 12: 257. 1992) and S. tenuicaule D. Yu & L. H. Liu (Bull. Bot. Res., Harbin 11(2): 19. 1991) are similar to this species. Because the two species were mainly described according to some quantitative characters and based on only one specimen, respectively, their taxonomic positions need to be further studied.