Plants aquatic, sometimes stranded, annual. Stems decum-bent, later ± erect if stranded, reddish in age, usually branched at base, to 14 cm, (rooting at basal nodes). Leaf blades oblanceolate to linear, 2-6 mm, apex acute. Inflorescences lax; flowers 1 per node. Pedicels 0.5-20 mm. Flowers 4-merous; sepals ovate to oblong, 0.5-1.5 mm, apex obtuse to rounded; petals ovate to oblong, 1-2 mm. Follicles erect, 6-17-seeded, oblong; old follicles spreading, flat. Seeds oblong-ellipsoid, (0.3-)0.4-0.5(-0.6) × 0.1-0.3 mm, not papillate, dull, minutely rugulose. 2n = 42 (Iceland).
Home