Barbarea orthoceras Ledeb.
American winter cress (American yellowrocket)
Brassicaceae (Mustard family)

Introduction to Vascular Plants


© Rosemary Taylor     (Photo ID #38441)


E-Flora BC Static Map

Distribution of Barbarea orthoceras
Click here to view the full interactive map and legend

Species Information

Biennial (occasionally perennial) from a taproot and a simple stem-base; stems stiff, erect, angled, branched, (10) 20-60 cm tall.
Basal leaves pinnately lobed, long-stalked, less than 12 cm long, with 1-5 pairs of lateral lobes, terminal lobe largest, egg-shaped and entire or irregularly toothed; stalks and sometimes leaflets long-fringed or sparsely short-hairy; lowermost stem leaves with 2-10 pairs of lateral lobes, upper pinnately cleft with the terminal lobe the largest, often clasping the stems.
In single and terminal racemes or more often in compound, reduced racemes in lower leaf axils; flower stalks not stout, less than 1 mm thick, 2-3 mm long; petals pale yellow, broadly spoon-shaped, 3-5 mm long; sepals pale yellow-green, about 2 mm long.
Erect to spreading-ascending siliques, (1.5) 2.5-5 cm long, straight; styles 0.5-1.5 mm long, not beaklike; seeds in 1 row, finely pitted, about 1.5 mm long.

SourceThe Illustrated Flora of British Columbia


If more than one illustration is available for a species (e.g., separate illustrations were provided for two subspecies) then links to the separate images will be provided below. Note that individual subspecies or varietal illustrations are not always available.


Ecological Framework for Barbarea orthoceras

The table below shows the species-specific information calculated from
original data (BEC database) provided by the BC Ministry of Forests and Range.
(Updated August, 2013)

Site Information
Value / Class




Elevation (metres)
587 61 1044
Slope Gradient (%)
12 0 100

Aspect (degrees)
[0 - N; 90 - E; 180 - S; 270 - W]

195 171 240
Soil Moisture Regime (SMR)
[0 - very xeric; 4 - mesic;
8 - hydric]
6 5 7
Modal Nutrient Regime
# of field plots
 species was recorded in:
Modal BEC Zone Class

All BEC Zones (# of stations/zone) species was recorded in

BG(1), BWBS(2), CDF(1), CWH(1), PP(1), SBS(1), SWB(1)

Habitat and Range

Moist streambanks, meadows and forests in the lowland, steppe and montane zones; common along the coast, less frequent elsewhere in BC; N to AK, YT and NT, E to NF, and S to MN, NH, CO, AZ and CA.

SourceThe Illustrated Flora of British Columbia


Synonyms and Alternate Names:
Barbarea americana Rydb.
Barbarea orthoceras var. dolichocarpa Fernald