Spirodela polyrhiza (Linnaeus) Schleiden. Greater Duckweed, Minnow-fole. Hab: Still to slowly moving waters of ponds, lakes, beaver ponds, and swamps. Dist: Widespread worldwide.

ID notes:The largest of the "duckweeds" (Landoltia, Lemna, Spirodela, Wolffia, Wolffiella).

Origin/Endemic status: Native

Taxonomy Comments: The spelling of the epithet is correctly 'polyrhiza', matching Linnaeus's basionym; there is no basis in the Code to change the spelling to 'polyrrhiza'.

Synonymy: = AqW, C, ETx1, F, G, GW1, K4, Mi, NcTx, NY, Ok, Pa, S, Tat, Tn, Tx, W, WH3, WV; = Spirodela polyrrhiza (L.) Schleid. – Ar, FNA22, GrPl, Il, K1, K3, NE, RAB, S13, Va, Landolt (1980), Landolt (1986), Les & Crawford (1999), Spaulding et al (2019), orthographic variant

Show in key(s)

Show parent genus

Wetland Indicator Status:

• Atlantic and Gulf Coastal Plain: OBL
• Eastern Mountains and Piedmont: OBL
• Great Plains: OBL
• Midwest: OBL
• Northcentral & Northeast: OBL

Heliophily: 7