European marshwort

Apium nodiflorum (now often Helosciadium nodiflorum), the European marshwort or fool’s watercress, is a hairless aquatic to semi-aquatic perennial in the family Apiaceae growing up to about 1 m tall. The thick, hollow, faintly ridged stems may be erect or trail across mud and shallow water, often streaked red or purple and rooting freely at the nodes. The glossy, pinnate leaves have four to six opposite pairs of toothed, oval to lanceolate leaflets and smell faintly of carrot when crushed. Small white flowers are borne in short-stalked compound umbels opposite the leaves from July to August, followed by tiny ridged mericarps typical of the family. Native to western Europe and the Mediterranean basin, it grows in ditches, slow streams, springs, fens, ponds and brackish estuarine margins, and is especially frequent in England, Wales and Ireland. Although superficially similar to and easily confused with the toxic lesser water parsnip Berula erecta, A. nodiflorum is not itself poisonous and has long been gathered as a wild salad herb.