Epilobium densiflorum (Lindl.) Hoch & P.H. Raven
dense spike-primrose (denseflower willowherb)
Onagraceae (Evening Primrose family)

Introduction to Vascular Plants


© Adolf Ceska     (Photo ID #11084)


E-Flora BC Static Map

Distribution of Epilobium densiflorum
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Species Information

Annual herb from a taproot; stems 15-100 cm tall, simple or branched above, peeling below; plant densely white-hairy to long soft- or stiff-hairy, sometimes glandular.
Alternate, except near base, lanceolate, becoming narrowly egg-shaped in the inflorescence,1-8.5 cm long, entire or remotely fine-toothed, upper ones hairy; unstalked or nearly so.
Inflorescence of crowded, densely-leafy, terminal and lateral spikes; hypanthium 1.5-4 mm long; petals 3-10 mm long, white to rose-purple, notched at tip; sepals 2-9 mm long; stigmas irregularly 4-lobed.
Capsules, more or less spindle-shaped, long-hairy, 0.4-1.1 cm long, very short-beaked, 4-chambered; valves split free of partition, the partition adhering to axis; seeds 3-6 per chamber, flattened, 1.2-2 mm long, netted, glabrous, brown, without tuft of hairs.

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.

Habitat and Range

Moist to dry meadows, roadsides and waste areas in the lowland zone; rare on S Vancouver Island; E to AB and S to MT, ID, NV, CA and MX.

SourceThe Illustrated Flora of British Columbia


Synonyms and Alternate Names:
Boisduvalia densiflora (Lindl.) S. Watson
Boisduvalia densiflora var. pallescens Suksd.
Boisduvalia densiflora var. salicina (Nutt. ex Torr. & A. Gray) Munz
Boisduvalia salicina (Nutt. ex Torr. & A. Gray) Rydb.
Oenothera densiflora Lindl.