Biennial herb from a stout taproot; forming rosette in first year and an erect, stiff stem in second; greyish stiff-hairy, also with spreading hairs from red blister-like bases; stems 50-200 cm tall, simple or branched.
Stem leaves alternate, ascending or spreading, lanceolate or elliptic, 10-30 cm long, entire to minutely-toothed, hairy.
Inflorescence a few-flowered, open spike, glandular, buds erect, opening in the evening, subtended by large bracts or reduced leaves; hypanthium 2.5-4 cm long; petals yellow, fading duller or pale orange, 0.7-2 cm long; sepals 0.9-1.8 cm long, often marked reddish, bent back when in flower, the free tips in bud 0.5-2.5 mm long.
Capsules, erect, narrowly lanceolate, 2-3.5 cm long, 4-7 mm wide, more or less straight, 4-chambered, hairy; seeds 1-2 mm long, angled, irregularly pitted.
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.
Illustration Source: The Illustrated Flora of British Columbia
Synonyms and Alternate Names:
Oenothera biennis var. strigosa (Rydb.) Piper
Oenothera cheradophila Bartlett
Oenothera depressa subsp. strigosa (Rydb.) Roy L. Taylor & MacBryde
Oenothera procera Woot. & Standl.
Oenothera rydbergii House
Oenothera strigosa (Rydb.) Mack. & Bush
Oenothera strigosa subsp. cheradophila (Bartlett) Munz
Oenothera villosa subsp. cheradophila (Bartlett) W. Dietr. & Raven
Oenothera villosa var. strigosa (Rydb.) Dorn