Duckweeds San Luis Obispo (1)
Home Keys To Genera List Of Species Search Lemna Spirodela Wolffia Wolffiella Wayne's Word
Duckweeds From San Luis Obispo
© W.P. Armstrong 23 January 2015
The following images were taken from live samples collected in San Luis Obispo County in December 2014 by Mark Elvin, U.S. Fish & Wildlife Service, Ventura, CA. Unfortunately, my identifications are somewhat tentative because I was unable to see several key features that were necessary to make a positive ID, particularly venation (nervation). This may be due, in part, to the time of year the duckweeds were collected. For several samples of Lemna with plant bodies 2 mm long and very obscure nerves (veins) I concluded they were simply L. minuta.

Elvin 7843

Elvin 7863

Elvin 7865

Elvin 7868

Duckweed Dilemma: Lemna turionifera or L. minor

Lemna turionifera typically has a row of minute papules on the upper (dorsal) side. It also has reddish anthocyanin on the underside and occasionally turions in the fall if you are lucky enough to find them still attached. Plants without a discernible row of papules are a dilemma. Are these plants L. minor, or are they L. turionifera with poorly developed papules? I just can't be 100% certain about the presence L. minor. Ideally, the ponds need to be resampled in the summer (or fall) when the duckweeds are in their optimal state of developent.

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