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

Epilobium anagallidifolium Lam.
alpine willowherb (pimpernel willowherb)
Onagraceae (Evening Primrose family)

Introduction to Vascular Plants

© Jamie Fenneman  Email the photographer   (Photo ID #30077)

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Distribution of Epilobium anagallidifolium
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Species Information

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Perennial herb from a fibrous root, tufted, somewhat mat-forming, with short stolons; stems ascending to erect, somewhat curved or S-shaped, 10-20 cm tall, green or reddish-tinged, sparsely short stiff-hairy in decurrent lines below, with some glandular hairs above, often with basal offshoots.
Opposite, narrowly elliptic to oblong or oblanceolate, 0.8-2.5 cm long, 2-9 mm wide, rounded at tips, entire to finely few-toothed, dark green or reddish-tinged, basal glabrous, upper sparsely short stiff-hairy on midrib and leaf margins; stalks obscure, 1-6 mm long.
Inflorescence a few-flowered, terminal raceme, often nodding; hypanthium 0.6-1.4 mm long; petals 2.5-6.5 (9) mm long, pink to rose-purple, rarely white, notched at tip; sepals 1.5-5 mm long, glabrous or sparsely glandular; anthers 0.3-0.6 mm long; ovaries 0.6-2 cm long, glabrous; styles 1.2-2.5 mm long; stigmas broadly club-shaped, rarely somewhat head-like.
Capsules, 1.7-3.6 cm long, about 1 mm wide, curved, nearly glabrous, red when ripe; seeds narrowly egg-shaped, 0.7-1.4 mm long, surface mostly net-veined, tuft of soft hairs persistent, 1.5-4 mm long, dull white.

Source: The Illustrated Flora of British Columbia

Habitat / Range

Mesic to wet mossy or rocky slopes, streambanks, gravel bars, seepage areas and open meadows in all vegetation zones; rare at low elevations, common at higher elevations throughout BC, especially northward; circumboreal, N to AK, YT and NT, E to NF, S to CA, CO and ME; Eurasia.

Source: The Illustrated Flora of British Columbia


Ecological Framework for Epilobium anagallidifolium

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) 20 1752 2563
Slope Gradient (%) 0 25 125
Aspect (degrees)
[0 - N; 90 - E; 180 - S; 270 - W]
0 204 360
Soil Moisture Regime (SMR)
[0 - very xeric; 4 - mesic;
8 - hydric]
0 4 8
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: AT(32), BAFA(73), BWBS(2), CMA(12), CWH(7), ESSF(310), ICH(11), IDF(6), IMA(17), MH(30), MS(14), SBPS(1), SBS(18), SWB(8)


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 alpine tundra & boreal.

Synonyms and Alternate Names

Epilobium alpinum L. p.p.
Epilobium anagallidifolium var. pseudoscaposum (Hausskn.) HultTn

Taxonomic and Nomenclatural Links

Additional Photo Sources

General References