E-Flora BC: Electronic Atlas of the Flora of British Columbia

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

Introduction to Vascular Plants

© Jamie Fenneman  Email the photographer   (Photo ID #29497)

E-Flora BC Static Map
Distribution of Cardamine occidentalis
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Species Information

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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.

Source: The Illustrated Flora of British Columbia

Habitat / Range

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

Source: The Illustrated Flora of British Columbia


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) 5 619 1530
Slope Gradient (%) 0 11 85
Aspect (degrees)
[0 - N; 90 - E; 180 - S; 270 - W]
18 56 360
Soil Moisture Regime (SMR)
[0 - very xeric; 4 - mesic;
8 - hydric]
1 5 7
Modal Nutrient Regime
Number 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)


The climate type for this species, as reported in the: "British Columbia plant species codes and selected attributes. Version 6 Database" (Meidinger et al. 2008), is cool mesothermal.

Synonyms and Alternate Names

Cardamine pratensis var. occidentalis S. Watson ex B.L. Rob.

Taxonomic and Nomenclatural Links

Additional Photo Sources

General References