That’s not a Duckweed

Ricciocarpos natans

Purple-fringed Riccia

Purple-fringed Riccia (Ricciocarpus natans) is not a flowering plant. It is an aquatic liverwort. It is found worldwide except where there is permanent ice. Floating on a pond it resembles a Duckweed and often grows with them. It differs in its butterfly shape and the fringe of purplish scales on the underside of the plants.

Ricciocarpos natans

Purple-fringed Riccia upper and lower surfaces

Duckweeds are flowering plants, capable of producing seeds. Purple-fringed Riccia reproduces via spores or plant division. Spores are produced inside the thallus. A thallus is a flat plant body not separated into stems and leaves. The plants are buoyant because they have many air chambers. A nice colony is found in Dragonfly Pond, Tenhave Woods, Royal Oak, Michigan. This is an interesting plant which should be sought in ponds throughout Michigan.

Ricciocarpos natans

Purple-fringed Riccia section showing air chambers and developing spores

Copyright 2016 by Donald Drife

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