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

Epilobium foliosum (Torr. & A. Gray) Suksd.
foliose willowherb (California willowherb)
Onagraceae (Evening Primrose family)

Introduction to Vascular Plants

© Jamie Fenneman  Email the photographer   (Photo ID #25067)

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Distribution of Epilobium foliosum
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Species Information

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Annual herb from a taproot; stems to 40 cm tall, more or less finely stiff-hairy, peeling somewhat below.
Opposite below, clustered above, nearly linear to lanceolate, 0.5-3 cm long, usually folded along midrib; stalks 3-12 mm long.
Inflorescence crowded, terminal, densely short stiff-hairy; hypanthium 0.4-0.8 mm long; petals 1.8-3 mm long, white, notched at tip; sepals 1.5-2.5 mm long.
Capsules, 1.2-2 cm long, sparsely hairy; stalks 2-5 mm long; seeds 0.6-0.9 mm long, pimply.
Similar to and often confused with E. minutum.

Source: The Illustrated Flora of British Columbia

Habitat / Range

Mesic to dry rock outcrops, meadows and grassy bluffs in the lowland and steppe zones; infrequent in S and W BC; S to CA.

Source: The Illustrated Flora of British Columbia


Ecological Framework for Epilobium foliosum

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) 810 810 810
Slope Gradient (%) 35 46 55
Aspect (degrees)
[0 - N; 90 - E; 180 - S; 270 - W]
118 178 250
Soil Moisture Regime (SMR)
[0 - very xeric; 4 - mesic;
8 - hydric]
0 1 2
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: IDF(1)


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 not evaluated, unknown or variable.

Synonyms and Alternate Names

Epilobium minutum var. foliosum Torr. & A. Gray

Taxonomic and Nomenclatural Links

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General References