Lemnaceae - Images of Lemna minor

	Home		Keys To Genera		List Of Species		Search		Lemna		Spirodela		Wolffia		Wolffiella		Wayne's Word

Lemna minor

Dorsal view (left) of mature plant with smooth surface (lacking papules). The plant at right with prominent apical papule is L. aequinoctialis.

See Images of Lemna aequinoctialis

Three duckweeds from Pinnacles National Monument in central California. A. Lemna minor: Three veins arising from point of root attachment (n), without dorsal row of papules and reddish anthocyanin on ventral side (as in L. turionifera) and without winged root sheath (as in L. aequinoctialis). B. Lemna valdiviana: One faint vein extending more than 3/4 distance from root node (n) to apex (red arrow), plant body very thin and transparent throughout and floating on or just below water surface (slipping under plant bodies of L. minor and L. minuta in an observation dish). C. Lemna minuta: One vein extending less than 2/3 distance from root node (n) to apex, vein not extending beyond region of larger air spaces (red arrow), plant body slightly thicker in middle (not as uniformly thin and transparent as L. valdiviana), small size (only 1-2 mm long) or larger when growing in shade, floating on water surface (not submersed as in L.valdiviana). Photo taken with substage illumination.

Duckweed from Lake Sutherland in San Diego County, California (collected by J.P. Rebman and J. Gregory in August 2004). This appears to be Lemna minor: It has three veins arising from point of root attachment (node), without dorsal row of papules and reddish anthocyanin on ventral side (as in L. turionifera) and without winged root sheath (as in L. aequinoctialis). Lemna gibba can be ruled out because the plant body is non-gibbous and without evidence of anthocyanin. The uninerved Lemna minuta and L. valdiviana can be ruled out because there are clearly three veins.

It is possible that the population also contains L. turionifera. The latter species is common throughout the inland mountains and valleys of San Diego County. Some of the smaller, younger plants had a faint row of dorsal papules similar to L. turionifera. Turions are typically produced during the fall months, and reddish anthocyanin is best observed during the peak growing season of summer. These two species are very similar. In fact, Dr. E. Landolt once classified them as L. minor I and L. minor II in his classic paper on the ecology and taxonomy of duckweeds in California [Landolt, E. 1957. Physiologische und ökologische Untersuchungen an Lemnaceed. Ber. Schweiz. Bot. Ges. 67: 271-410.] Landolt later described L. minor 1 as Lemna turionifera.

Return To The Lemnaceae Home Page
Go To Keys To The Genera Of Lemnaceae
Go To The List Of Species Of Lemnaceae
Go To The List Of .GIF Images Of Lemnaceae
Go To The WAYNE'S WORD Home Page