Lemna obscura

(Austin) Daubs

Illinois Biological Monographs 34: 20. 1965.

Basionym: Lemna minor var. obscura Austin in A. Gray, Manual ed. 5, 479. 1867
Treatment appears in FNA Volume 22.

Roots to 15 cm, tip mostly rounded; sheath not winged. Stipes white, small, often decaying. Fronds floating, 1 or 2–5 or more, coherent in groups, obovate, flat or gibbous, 1–3.5 mm, 1–1.5 times as long as wide, margins entire; veins 3, greatest distance between lateral veins near middle; very distinct papillae near apex, some smaller indistinct ones on midline of upper surface; lower surface very often red colored (more intensely than on upper), coloring beginning at attachment point of root, lower upper surface sometimes with red spots; air spaces shorter than 0.3 mm; distinct turions absent. Flowers: ovaries 1-ovulate, utricular scale with narrow opening at apex. Fruits 0.5–0.7 mm, not winged. Seeds with 10–16 distinct ribs, staying within fruit wall after ripening. 2n = 40, 42, 50.

Phenology: Flowering (occasional) spring–fall.
Habitat: Mesotrophic to –eutrophic, quiet waters, in temperate to subtropical regions with mild winters
Elevation: 0–800 m


V22 253-distribution-map.jpg

Ala., Ark., Del., D.C., Fla., Ga., Ill., Ind., Iowa, Kans., Ky., La., Md., Minn., Miss., Mo., Nebr., N.J., N.Y., N.C., Ohio, Okla., Pa., S.C., S.Dak., Tenn., Tex., Va., Wis., c Mexico, South America (Colombia, Ecuador), Hawaii.


Selected References


Lower Taxa

... more about "Lemna obscura"
Elias Landolt +
(Austin) Daubs +
Lemna minor var. obscura +
Ala. +, Ark. +, Del. +, D.C. +, Fla. +, Ga. +, Ill. +, Ind. +, Iowa +, Kans. +, Ky. +, La. +, Md. +, Minn. +, Miss. +, Mo. +, Nebr. +, N.J. +, N.Y. +, N.C. +, Ohio +, Okla. +, Pa. +, S.C. +, S.Dak. +, Tenn. +, Tex. +, Va. +, Wis. +, c Mexico +, South America (Colombia +, Ecuador) +  and Hawaii. +
0–800 m +
Mesotrophic to –eutrophic, quiet waters, in temperate to subtropical regions with mild winters +
Flowering (occasional) spring–fall. +
Illinois Biological Monographs +
Weedy +  and Illustrated +
Lemna obscura +
species +