Cardamine occidentalis (S. Watson ex B.L. Rob.) Howell
western bitter-cress (big western bittercress)
Brassicaceae (Mustard family)

Introduction to Vascular Plants


© Jamie Fenneman     (Photo ID #29497)


E-Flora BC Static Map

Distribution of Cardamine occidentalis
Click here to view the full interactive map and legend

Species Information

Perennial herb from a short, slender rhizome; stems 1-1.5 mm thick, enlarged and tuberous near base of leafy stems, 20-40 cm tall, simple to freely branched, erect to decumbent and rooting at nodes, glabrous to sparsely hairy.
Basal leaves few, slender-stalked, pinnate, lateral lobes (2) 4-6, egg-shaped to heart-shaped, short-stalked to unstalked, 3-8 mm long, generally entire, terminal lobe 1-2 cm long, shallowly wavy-margined; stem leaves several, upper ones unstalked to nearly unstalked, fewer lateral lobes, narrowly egg-shaped to linear, mostly 1-2 cm long, entire or slightly toothed, terminal leaflet egg- to wedge-shaped, 1.5-3 cm long.
Inflorescence an elongate raceme, without bracts; flower stalks ascending, 10-15 mm long; petals white, 3.5-5 mm long; sepals 1-2 (2.5) mm long.
Siliques, erect, 2-3 cm long, 1-1.5 mm wide; styles about 1 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 Cardamine occidentalis

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)
619 5 1530
Slope Gradient (%)
11 0 85

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

56 18 360
Soil Moisture Regime (SMR)
[0 - very xeric; 4 - mesic;
8 - hydric]
5 1 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

CDF(13), CWH(11), ESSF(3), ICH(7), IDF(1), MH(4), MS(1), SBS(7)

Habitat and Range

Wet to moist streambanks and lakeshores in the lowland zone; infrequent in SW BC; N to AK and S to CA.

SourceThe Illustrated Flora of British Columbia


Synonyms and Alternate Names:
Cardamine pratensis var. occidentalis S. Watson ex B.L. Rob.