''Helosciadium nodiflorum'' (synonym: ''Apium nodiflorum''), fool's watercress, is a flowering plant found in ditches or streams, as well as fresh and brackish-water wetlands native to western Europe. It is not poisonous to humans but it could be easily confused with the allegedly poisonous lesser water parsnip.

Description

''Helosciadium nodiflorum'' is a low-growing or prostrate hairless perennial up to 1 m tall, with a thick, hollow, faintly ridged stem which, when lying down (procumbent) produces roots at the nodes. It has glossy

pinnate Pinnation (also called pennation) is the arrangement of feather-like or multi-divided features arising from both sides of a common axis. Pinnation occurs in biological morphology, in crystals, such as some forms of ice or metal crystals, and in ...

leaves, each of which has 4-6 opposite pairs of toothed, oval to lanceolate leaflets that are slightly paler green on the undersides. There are ridges at the nodes of the leaflets which are often paler than the rhachis and look like rings. (Note, this is different from lesser water-parsnip, which has a ring on the petiole.) The petioles are hollow with a distinctive single groove on upper surface, and may be streaked with red/purple lines; they are laterally inflated towards the base and clasp the stem. The crushed leaves smell of carrot. Helosciadium nodiflorum2

Taxonomy

In 2010 a taxonomic revision demonstrated that the genus ''Apium'' was

polyphyletic A polyphyletic group is an assemblage of organisms or other evolving elements that is of mixed evolutionary origin. The term is often applied to groups that share similar features known as homoplasies, which are explained as a result of conver ...

and needed to be split into three genera. Five of the 7 European species of ''Apium'' were therefore moved to the genus ''Helosciadium'', as had first been proposed by Wilhelm Koch in 1824. ''Apium nodiflorum'' was among them, and is therefore now correctly called ''Helosciadium nodiflorum'' W.D.J. Koch. The genus is noted for the high rate of hybridization between its species, and the following hybrids have been described: * × ''Beruladium procurrens'' A.C. Leslie (''Berula erecta'' × ''H. nodiflorum'') * ''Helosciadium × moorei'' (Syme) Warren (''Helosciadium inundatum'' (L.) W.D.J. Koch ''× H. nodiflorum)'' * ''Helosciadium × longipedunculatum'' (F.W. Schultz) Desjardins (''Helosciadium repens'' (Jacq.) W.D.J. Koch ''× H. nodiflorum'') * ''Helosciadium × clandestinum'' Rita, Capó & Cursach ('' Helosciadium bermejoi'' (L. Llorens) Popper & M.F. Watson × ''H. nodiflorum'')

Distribution and habitat

''Helosciadium nodiflorum'' is common throughout England, Wales and Ireland but much less so in Scotland. It often grows with

watercress Watercress or yellowcress (''Nasturtium officinale'') is a species of aquatic flowering plant in the cabbage family Brassicaceae. Watercress is a rapidly growing perennial plant native to Europe and Asia. It is one of the oldest known leaf v ...

in wet places. It blooms in July and August and is found in wet habitats including ditches, springs, fens and ponds. The species is also widely documented from brackish estuarine/salt marsh habitats.

Uses

Wild fool's watercress has been traditionally harvested and consumed in several Mediterranean countries, including Spain, Italy, Portugal and Morocco The edible young leaves and tender shoots can be used raw in salads, boiled, or used as a condiment in soups and other dishes.

References

External links

{{Taxonbar, from=Q964806 nodiflorum Freshwater plants Flora of Europe Flora of Western Asia Flora of the Arabian Peninsula Flora of North Africa Flora of the Canary Islands