General: Perennial, aquatic, emergent herb from an extensive creeping rhizome; stems erect, simple but sometimes shortly branched from the lower nodes, glabrous, 1.5-5 mm wide, 5-40 cm tall, above water partly.
Leaves: Stem leaves 8-12 per whorl, linear, glabrous, pointed at the tips, 6-35 mm long, 1-2 mm wide.
Flowers: Inflorescence of tiny, mostly bisexual flowers in several whorls in the axils of the leaf whorls, stalked below, unstalked in the upper leaf axils; anthers 1.2 mm long; mature ovaries about 2 mm long.
1. Stems 1.5-8 (10) cm tall, less than 1 mm wide; leaves 2-6 (10) mm long.......................H. montana
1. stems 10-40 cm tall, 1.5-5 mm wide; leaves 6-30 (50) mm long.
2. Leaves elliptic to oblong or egg-shaped, and blunt-tipped, 6-15 mm long, 2-8 mm wide, 4-6 (8) per whorl.............................H. tetraphylla
2. Leaves linear and slender-tipped, 6-30 (50) mm long, 1-2 mm wide, (6) 8-12 per whorl...............................H. vulgaris
Source: Illustrated Flora of British Columbia
Habitat / Range
Streamsides, lake shores and shallow ponds in the lowland, steppe and montane zones; common throughout BC, less frequent along the coast; circumpolar, N to AK, YT and NT, E to Labr. and S to IN, NB, NM and CA; Chile, Argentina and Eurasia.
The table below shows the species-specific information calculated from original data (BEC database) provided by the BC Ministry of Forests and Range. (Updated August, 2013)