Northern Prairie Wildlife Research Center
Aquatic and Wetland Vascular Plants of the Northern Great Plains
Najas L. -- Naiad
Small, submersed, monoecious or dioecious, perennial herbs; stems flexuous,
freely branched, anchored by roots. Leaves simple, opposite, sessile,
abruptly broadened at the base to sheath the stem, the margins faintly to coarsely
toothed. Flowers minute, imperfect, solitary and sessile in the leaf
axils, enclosed by the sheathing leaf bases; male flowers consisting
of a single anther enclosed in a membranous envelope, this in turn surrounded
by a firmer, entire to 4-lobed, perianthlike structure; female flowers
comprised of a single, 1-ovuled pistil, stigmas 2-4, style usually elongate
and persistent. Fruit a fusiform achene, the pericarp thin and easily
removed to expose the single ellipsoid seed.
Clausen, R. T. 1936. Studies in the genus Najas in the
northern United States. Rhodora 38:333-345.
||Leaves coarsely spinulose-toothed; seeds 4-5 mm
||Leaves very faintly toothed; seeds 2-3 mm long.
||Seed coat (under the thin pericarp) shiny, very
faintly reticulate, with 30-40 rows of obscure pits across the middle;
style beak of achene 1 mm or more long.
||Seed coat rather dull, coarsely reticulate, with
10-20 rows of pits across the middle; style beak of mature achene 0.5
mm or less long.
57. Najadaceae, the Naiad Family
1. Najas L. -- Naiad
- 1. Najas flexilis (Willd.) Rostk.
- 2. Najas guadalupensis (Spreng.) Magnus.
-- Southern naiad
- 3. Najas marina L.
Return to Family -- Najadaceae - The Naiad Family
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