General:
Annual herb from fibrous roots; stems erect or sprawling, 2-45 cm tall.

Leaves:
Located on the lower part of the stem, nearly circular in cross-section, lacking cross-walls.

Flowers:
Inflorescence terminal, open, commonly much branched, long, forming about 1/2 to 3/4 of the plant height, with many single flowers; perianth segments green, 2.5-6 mm long, pointed, about equal; stamens 6; anthers 0.5-1 mm long, shorter than the filaments; lower bract leaflike, nearly circular in cross-section, tapered, usually shorter than the inflorescence.

Fruits:
Capsules, cylindrical to nearly globe-shaped, pointed, shorter than the perianth segments; seeds barrel-like, about 0.4 mm long, lacking tail-like appendages.

Notes:
Variable species with a large number of chromosomal races. Several taxa within this complex have been described and treated as distinct species or varieties.

Source:  The Illustrated Flora of British Columbia