American Wintercress

American Rocket, American Yellowrocket
Barbarea orthoceras
NATIVE

Description (Jepson, PlantID.net)

• Eudicotyledon
  • Eudicots are a major lineage of flowering plants; see family for general characteristics
• Mustard Family (Brassicaceae)
• Perennial herb
• Stems are erect, with ridges
• Leaves
  • Form a basal rosette and occur along the stem, reducing upward
    • Each leaf is divided into 1-4 leaflet pairs (pinnately compound), with a larger terminal leaflet
    • Leaflets may be wavy edged and sparsely toothed
  • Stem (cauline) leaves attach directly to the stem (sessile)
• Flowers
  • Inflorescence (flower arrangement) is a raceme (unbranched stem with stalked flowers opening from the bottom up)
  • Each flower with 4 yellow petals forming a cross
  • 6 stamens (male flower parts), 4 long and 2 short
  • Sepals (outer flower parts) yellow to yellow green
  • Ovary superior (above the attachment of other flower parts)
• Fruit is an upright silique (long, narrow pod) with a horn-shaped tip
• Height to 20 in.

Distribution

• Native to California
  • Grows predominately in moist areas
  • See Calflora for statewide observations of this plant
• Outside California, grows in Western North America, and in parts of central and eastern Asia
• Grows at elevations to 11,000 ft.

Uses (San Mateo County Parks prohibits removal of any natural material)

• Wildlife
  • Visited by flies, bees, and beetles
  • Larval food source (host) for several butterfly species, e.g. Sara orangetip (Anthocharis sara) and checkered white (Pontia protodice)
• Human
  • Leaves can be eaten raw or cooked

Name Derivation

• Barbarea (bar-BARE-ee-a) – named after St. Barbara, a 3rd-century Greek Christian martyr
• orthoceras (or-tho-SER-as) – from the Greek órthios, “straight, upright” and kéras, “horn,” referring to the horn-tipped fruit
• Wintercress – common name for plants in this genus
  • Cress is a name associated with cruciferous plants (Mustard family)
• Rocket – common name for many plants in the Mustard family
  • From the Italian ruchetta or rucola, a diminutive of the Latin eruca, once a name for a kind of mustard plant and now a genus in the Mustard family, which includes the leafy vegetable arugula or rocket (Eruca vesicaria)

Notes

• Crushed plant tissue of most Mustard species release peppery-smelling, pungent-tasting isothiocyanates (cyanide compounds), derived from glucosinolates (Ishida 2014); see Mustard family for more details

ID Tips

• May be confused at Edgewood with 2 yellow-flowering, non-native mustards — short-podded mustard (Hirschfeldia incana) and hedge mustard (Sisymbrium officinale)

	American Wintercress	Hedge Mustard	Short-podded Mustard
Growth Habit	perennial herb	annual herb	perennial herb
Height	≤ 20 in.	≤ 24 in.	≤ 31 in.
Hairy Stem	no	sometimes	yes
Basal Leaf Terminal Lobe	broad-rounded tip	acutely-pointed tip	broad-rounded tip
Flower Stalk	erect, compact	laterally sprawling	laterally sprawling
Fruit	not appressed to stem	appressed to stem	appressed to stem
Habitat	woodland	disturbed areas	disturbed areas

At Edgewood

• Found in woodlands
  • See iNaturalist for observations of this plant
• Flowers March – July

Specific References

Ishida, M., et al. 2014. Glucosinolate metabolism, functionality and breeding for the improvement of Brassicaceae vegetables. Breeding science, 64: 48–59. J-STAGE.

General References

Calflora Database. 2014. Berkeley, California.

Calscape. 2018. California Native Plant Society.

Charters, M.L. 2015. California Plant Names: Latin and Greek Meanings and Derivations.

Charters, M.L. 2017. Southern California Wildflowers: Guide to the Pronunciation of Specific, Generic and Family Names.

Corelli, T. 2004. Flowering Plants of Edgewood Natural Preserve (2nd. ed.). Monocot Press, Half Moon Bay, California.

Dave’s Garden.

Elpel, T.J. 2013. Botany in a Day: The Patterns Method of Plant Identification. HOPS Press, Pony, Montana.

Flora of North America. efloras.org.

Harris, J.G. and M.W. Harris. 2013. Plant Identification Terminology: An Illustrated Glossary. Spring Lake Publishing, Spring Lake, Utah.

Keator, G. 2009. California Plant Families. University of California Press, Berkeley and Los Angeles, California.

Native American Ethnobotany DB.

Regents of the University of California. Jepson eFlora. Jepson Herbarium. University of California, Berkeley.