Aquatic and Wetland Vascular Plants of the Northern Great Plains
57. Najadaceae, the Naiad Family
1. Najas L. -- Naiad
3. Najas marina L.
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.
Jul--Sep. Shallow water of brackish lakes and marshes; rare, with collections
from Lake Elsie and Mud Lake, Richland Co., ND; also in some lakes of w MN;
(Nearly cosmopolitan, but quite localized in N.Amer.; NY, FL, TX, UT, AZ, NV
and CA, as well as our area).