Burke: Lemna minor vs. Lemna minuta

	Lemna minor	Lemna minuta
	common duckweed, lesser duckweed, water lentil	least duckweed
Habit	Floating aquatic perennials forming colonies, ovate body 1-8 mm long, flat and barely gibbous, margins entire, rarely slightly reddish beneath, sometimes diffusely red above; stipes small, white, usually decaying; roots 15 cm or shorter, sheath not winged.	Floating aquatic perennials forming colonies, lanceolate-ovate body 0.8-4 mm long, flat to somewhat thick, margins entire; stipes small, white, usually decaying; roots to 1.5 cm, tip rounded or pointed, sheath not winged.
Leaves	None	None
Flowers	Plants rarely found in flower, reproducing vegetatively; flowers 1-2 per body, surrounded by a utricular, membranous scale; stamens 2, 4-chambered; ovaries 1, containing 1 ovule, tapering into style, stigma funnel-shaped.	Plants rarely found in flower, reproducing vegetatively; flowers 1-2 per body, surrounded by utricular scale open on 1 side; stamens 2, 4-chambered, ovaries 1, containing 1 ovule, tapering into style, stigma funnel-shaped.
Fruits	Fruit a follicle, 0.8-1 mm, laterally winged toward tip, opening by bursting; seeds 1-5, with 8-15 ribs.	Fruit a follicle, 0.6-1 mm, not winged, opening by bursting; seeds 1-5, with 12-15 distinct ribs.

	Lemna minor	Lemna minuta
Flowering time	June - October	June-September
Habitat	In standing or slow-moving fresh water	Floating on surface of calm water or on face of vertical rock seeps.
Distribution	Occurring on both sides of the Cascades crest in Washington; Alaska to California, east across North America to the Atlantic Coast; cosmopolitan. [WildflowerSearch map] [BONAP county map]	Occurring chiefly west of the Cascades crest and in the Columbia River Gorge in Washington; southwestern British Columbia to California, east across the U.S. in scattered locations to the Atlantic Coast. [WildflowerSearch map] [BONAP county map]
Origin	Native	Native
Conservation status	Not of concern	Not of concern
Sibling taxa	L. minuta, L. trisulca, L. turionifera	L. minor, L. trisulca, L. turionifera
Web links	Local floras: BC, CA, OR, WA Local Web sites: CalFlora, CalPhotos, Flora NW, PNW Herbaria WildflowerSearch iNaturalist (observations) USDA Plants Database LBJ Wildflower Center SEINet Plants of the World Online Encyclopedia of Life Wikipedia Google Image Search	Local floras: BC, CA, OR, WA Local Web sites: CalFlora, CalPhotos, Flora NW, PNW Herbaria WildflowerSearch iNaturalist (observations) USDA Plants Database LBJ Wildflower Center SEINet Plants of the World Online Encyclopedia of Life Wikipedia Google Image Search

Lemna minuta

common duckweed, lesser duckweed, water lentil

least duckweed

Habit

Floating aquatic perennials forming colonies, ovate body 1-8 mm long, flat and barely gibbous, margins entire, rarely slightly reddish beneath, sometimes diffusely red above; stipes small, white, usually decaying; roots 15 cm or shorter, sheath not winged.

Floating aquatic perennials forming colonies, lanceolate-ovate body 0.8-4 mm long, flat to somewhat thick, margins entire; stipes small, white, usually decaying; roots to 1.5 cm, tip rounded or pointed, sheath not winged.

Leaves

None

Flowers

Plants rarely found in flower, reproducing vegetatively;

flowers 1-2 per body, surrounded by a utricular, membranous scale;

stamens 2, 4-chambered;

ovaries 1, containing 1 ovule, tapering into style, stigma funnel-shaped.

Plants rarely found in flower, reproducing vegetatively;

flowers 1-2 per body, surrounded by utricular scale open on 1 side;

stamens 2, 4-chambered, ovaries 1, containing 1 ovule, tapering into style, stigma funnel-shaped.

Fruits

Fruit a follicle, 0.8-1 mm, laterally winged toward tip, opening by bursting;

seeds 1-5, with 8-15 ribs.

Fruit a follicle, 0.6-1 mm, not winged, opening by bursting;

seeds 1-5, with 12-15 distinct ribs.

Lemna minor

Lemna minuta

Flowering time

June - October

June-September

Habitat

In standing or slow-moving fresh water

Floating on surface of calm water or on face of vertical rock seeps.

Distribution

Occurring on both sides of the Cascades crest in Washington; Alaska to California, east across North America to the Atlantic Coast; cosmopolitan.

[WildflowerSearch map]

[BONAP county map]

Occurring chiefly west of the Cascades crest and in the Columbia River Gorge in Washington; southwestern British Columbia to California, east across the U.S. in scattered locations to the Atlantic Coast.

[WildflowerSearch map]

[BONAP county map]

Origin

Native

Conservation status

Not of concern

Sibling taxa

L. minuta, L. trisulca, L. turionifera

L. minor, L. trisulca, L. turionifera

Web links