mermaidweed

Mermaidweed is a common name used for several aquatic plants, most notably species within the genus Proserpinaca. The most widely recognized species is Proserpinaca palustris, commonly known as marsh mermaidweed. This submerged or emergent aquatic herb is found in slow-moving fresh and brackish waters throughout much of North and South America.

Marsh mermaidweed typically grows with delicate, feathery submerged leaves that are pinnately compound and often reddish in coloration. When growing emerged, its leaves become broader and more toothed. The plant produces small, inconspicuous flowers that grow in the leaf axils. It reproduces both vegetatively through fragmentation and by seed.

Mermaidweed plays a role in aquatic ecosystems by providing habitat and food for various invertebrates and fish. It is also sometimes used in aquariums, where its colorful submerged form can be attractive. The term "mermaidweed" likely derives from the plant's delicate, flowing appearance underwater, reminiscent of mermaid's hair. Other plants may occasionally be referred to by this common name, but Proserpinaca palustris is the most prevalent association.