Burke: Lemna minor vs. Lemna trisulca

	Lemna minor	Lemna trisulca
	common duckweed, lesser duckweed, water lentil	ivy duckweed, ivy-leaved duckweed, star 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.	Monoecious, fleshy, colonial perennials without stem or leaves, the plant a free-floating or submersed, oblong-elliptic to elliptic-lanceolate body 6-12 mm. long, with an equally-long, stalk-like base, the bodies tending to remain connected and forming large mats.
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 usually 3, 2 staminate and 1 pistillate, together in a marginal cleft of the body, the staminate a single stamen with a 2-celled anther, the pistillate a single carpel with a 1-celled ovary.
Fruits	Fruit a follicle, 0.8-1 mm, laterally winged toward tip, opening by bursting; seeds 1-5, with 8-15 ribs.	Fruit a utricle.

	Lemna minor	Lemna trisulca
Flowering time	June - October	July-September
Habitat	In standing or slow-moving fresh water	Quiet streams and standing fresh water.
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 on both sides of the Cascades crest in Washington; Alaska to California, east across much of North America to the Atlantic Coast; cosmopolitan. [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. minuta, 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 trisulca

common duckweed, lesser duckweed, water lentil

ivy duckweed, ivy-leaved duckweed, star 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.

Monoecious, fleshy, colonial perennials without stem or leaves, the plant a free-floating or submersed, oblong-elliptic to elliptic-lanceolate body 6-12 mm. long, with an equally-long, stalk-like base, the bodies tending to remain connected and forming large mats.

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 usually 3, 2 staminate and 1 pistillate, together in a marginal cleft of the body, the staminate a single stamen with a 2-celled anther, the pistillate a single carpel with a 1-celled ovary.

Fruits

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

seeds 1-5, with 8-15 ribs.

Fruit a utricle.

Lemna minor

Lemna trisulca

Flowering time

June - October

July-September

Habitat

In standing or slow-moving fresh water

Quiet streams and standing fresh water.

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

[WildflowerSearch map]

[BONAP county map]

Origin

Native

Conservation status

Not of concern

Sibling taxa

L. minuta, L. trisulca, L. turionifera

L. minor, L. minuta, L. turionifera

Web links