Common name: Evening Primrose
Oenothera biennis L. APNI*
Description: Coarse biennial forb, forming basal rosette the first year and becoming many branched in the second year. Stems erect, hairy, green to reddish; 0.5 to 1.6 m tall.
Leaves lanceolate to oblong, acute, tapering to the base, up to 15 cm long and about 5 cm broad; margins sometimes wavy, with or without small teeth; upper surface green, rough-hairy; lower surface hairy with prominent veins. Rosette leaves (first year) long-petioled; cauline leaves alternate, sessile.
Flowers clustered in the upper axils, 3.25 cm long, 2.5–5 cm wide. Petals 4 free, yellow; sepals 4 green, hairy, reflexed; stamens 8; stigma cross-shaped.
Fruit a cylindrical capsule, usually hairy; up to 5 cm long, 3.5 to 6 cm wide near the base. Seeds numerous, reddish, 2 to 3 mm long.
Flowering: Flowers spring to autumn.
Distribution and occurrence: Becoming naturalised in the Blue Mountains.
NSW subdivisions: *CT
Text by Peter G. Wilson (2004)
APNI* Provides a link to the Australian Plant Name Index (hosted by the Australian National Botanic Gardens) for comprehensive bibliographic data
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