Wolffia: Named after Johann Friedrich Wolff, 18th century German botanist and physician
australiana: From the Latin australis meaning southern
Current Threat Status
2012 - Not Threatened
Previous Threat Status
2009 - Not Threatened
2004 - Not Threatened
Wolffia australiana (Benth.) Hartog et Plas
Vascular - Native
Wolffia arrhiza var. australiana Benth.
Indigenous. North, South and Chatham Islands. Found throughout the Southern Hemisphere but exact distribution not clear
Coastal to lower montane (up to 400 m a.s.l.) in still, fertile, water in sunny situations. Often found in association with Lemna minor L., Landoltia punctata (G.Mey.) Les et D.J.Crawford, Azolla filiculoides Lam., Ricciocarpos natans (L.) Corda and Riccia fluitans L. Easily overlooked.
Bright green, minute aquatic summer-green herb without roots. Platelets 0.3-1 mm long, bearing one vegetative bud per platelet, ellipsoidal, dorsal surface weakly convex, the central green part merging into a colourless rounded shoulder; submerged portion much larger than that above water, pale, loosely cellular, more or less semi-circular in side view but laterally compressed. Inflorescence in a cavity opening on upper platelet surface; bearing one male and one female flower united without spathe. Ovule 1. Fruit spherical. Seed smooth with prominent operculum.
None. Could be confused with Lemna and Landlotia from which it differs by its much smaller size, absence of roots, uniformly green colour without red or purple pigmentation, and by the platelets bearing only one vegetative bud
November - February
December - April
Easily grown in a suitable pond, pool or aquarium. During winter it sinks to the bottom sediment, and becomes dormant, returning to surface during warmer weather in late spring and summer.
2n = 20, 40
This page last updated on 20 Jan 2014