Najas marina

Detailed description

Plants dioecious; stems freely branched, 2-5 dm long, the internodes often spinulose. Leaves linear, coarsely spinulose-toothed, sometimes spinulose on the back, 10-20 mm long, 2-4 mm wide (including the teeth), the teeth triangular, projecting 0.5-1 mm, 1-4 mm apart. Achenes olive-green, the beak 0.5-1.5 mm long. Seeds 4-5 mm long, 1/2 as thick, finely reticulate.