Burke: Oenothera laciniata vs. Oenothera biennis

	Oenothera laciniata	Oenothera biennis
		King's-cureall, common evening primrose
Habit		Grayish biennial or short-lived perennial, the stems 3-10 dm. tall, erect, simple or freely-branching, with short, appressed hairs and longer, spreading, reddish-based hairs.
Leaves		Leaves alternate, the lower leaves petiolate, the upper sub-sessile, lanceolate, 1-2.5 cm. broad, entire to wavy-dentate.
Flowers		Inflorescence an elongate spike, the buds erect, with bracts more or less the length of the capsules; calyx tube 3-5 cm. long, the 4 lobes 10-15 mm. long, reflexed, distinct; petals 4, yellow, 1-2 cm. long; stamens 8, equal to the petals and style; stigma with 4 linear lobes 4-7 mm. long; ovary inferior, 4-celled.
Fruits		Capsule 2.5-4 cm. long, linear, cylindrical.

	Oenothera laciniata	Oenothera biennis
Flowering time		June-August
Habitat		Meadows and stream banks, from the plains to the lower mountains, typically where disturbed.
Distribution	[WildflowerSearch map] [BONAP county map]	Occurring on both sides of the Cascades crest in Washington; widely distributed throughout much of North America. [WildflowerSearch map] [BONAP county map]
Origin		Introduced from Europe
Conservation status		Not of concern
Sibling taxa	O. biennis, O. cespitosa, O. curtiflora, O. elata, O. flava, O. glazioviana, O. pallida, O. suffrutescens	O. cespitosa, O. curtiflora, O. elata, O. flava, O. glazioviana, O. pallida, O. suffrutescens
Web links	Local floras: CA Local Web sites: CalFlora, CalPhotos, Flora NW, PNW Herbaria WildflowerSearch iNaturalist (observations) USDA Plants Database LBJ Wildflower Center SEINet Plants of the World Online Encyclopedia of Life Wikipedia Google Image Search	Local floras: BC, CA, OR, WA Local Web sites: CalFlora, CalPhotos, Flora NW, PNW Herbaria, Turner Photog. WildflowerSearch iNaturalist (observations) USDA Plants Database LBJ Wildflower Center SEINet Plants of the World Online Encyclopedia of Life Wikipedia Google Image Search

Oenothera laciniata

Oenothera biennis

King's-cureall, common evening primrose

Habit

Grayish biennial or short-lived perennial, the stems 3-10 dm. tall, erect, simple or freely-branching, with short, appressed hairs and longer, spreading, reddish-based hairs.

Leaves

Leaves alternate, the lower leaves petiolate, the upper sub-sessile, lanceolate, 1-2.5 cm. broad, entire to wavy-dentate.

Flowers

Inflorescence an elongate spike, the buds erect, with bracts more or less the length of the capsules;

calyx tube 3-5 cm. long, the 4 lobes 10-15 mm. long, reflexed, distinct;

petals 4, yellow, 1-2 cm. long;

stamens 8, equal to the petals and style;

stigma with 4 linear lobes 4-7 mm. long;

ovary inferior, 4-celled.

Fruits

Capsule 2.5-4 cm. long, linear, cylindrical.