Nasturtium (plant genus)

This article is about the genus of watercresses. For the flowering plants of the genus Tropaeolum, commonly called nasturtiums, see Tropaeolum. For other uses, see Nasturtium (disambiguation).

Nasturtium (/nəˈstɜːrʃəm/) is a genus of a small number of plant species in the family Brassicaceae (cabbage family) commonly known as watercress or yellowcress.^[2] The best known species are the edible Nasturtium officinale and Nasturtium microphyllum. Nasturtium was previously synonymised with Rorippa, but molecular evidence supports its maintenance as a distinct genus more closely related to Cardamine than to Rorippa sensu stricto.^[3][4]

Nasturtium
Nasturtium microphyllum, a watercress, in Hawai'i
Scientific classification
Kingdom:	Plantae
Clade:	Tracheophytes
Clade:	Angiosperms
Clade:	Eudicots
Clade:	Rosids
Order:	Brassicales
Family:	Brassicaceae
Genus:	Nasturtium W.T.Aiton[1]
Species
See text.

These plants are related to garden cress and mustard, noteworthy for a peppery, tangy (pungent) flavor. The name Nasturtium comes from the Latin nasus tortus, meaning "twisted nose", in reference to the effect on the nasal passages of eating the plants. Nasturtium foliage is used as food by the caterpillars of certain Lepidoptera, including Orthonama obstipata (The Gem).

One species, Nasturtium gambellii, is federally listed in California as an endangered species.^[5]

Nomenclature

The genus Nasturtium should not be confused with the ornamental garden plant, usually grown as an annual, that is commonly known as nasturtium (Tropaeolum majus). Though not closely related, the leaves of the garden nasturtium also have a peppery taste.

Species

As of June 2022^[update], Plants of the World Online accepts the following species and hybrids:^[1]

• Nasturtium floridanum (Al-Shehbaz & Rollins) Al-Shehbaz & R.A.Price – Florida watercress or Florida yellowcress
• Nasturtium gambellii (S.Watson) O.E.Schulz (orth. var. N. gambelii) – Gambel's watercress or Gambel's yellowcress
• Nasturtium microphyllum (Boenn.) Rchb. – onerow watercress or onerow yellowcress
• Nasturtium officinale W.T.Aiton – watercress or yellowcress
• Nasturtium × sterile (Airy Shaw) Oefelein – N. officinale × N. microphyllum, hybrid watercress^[6]

Plants of the World Online regards Nasturtium africanum as a synonym of Rorippa africana.^[7]