From Wikipedia, the free encyclopedia

Oenothera biennis
Scientific classification
Kingdom:	Plantae
Division:	Magnoliophyta
Class:	Magnoliopsida
Order:	Myrtales
Family:	Onagraceae
Genus:	Oenothera
Species:	O. biennis
Binomial name
Oenothera biennis L.

Oenothera biennis (Common evening primrose or Evening star) is a species of Oenothera native to eastern and central North America, from Newfoundland west to Alberta, southeast to Florida, and southwest to Texas, and widely naturalized elsewhere in temperate and subtropical regions.^[1]

Growth

rosette

flowers and fruit capsules

It is a biennial flowering plant growing to 30–150 cm tall. The leaves are lanceolate, 5–20 cm long and 1–2.5 cm broad, produced in a tight rosette in the first year, and spirally on the stem in the second year. The flowers are pale yellow, 2.5–5 cm diameter, with four petals; they are hermaphrodite, and produced on a tall spike from late spring to late summer. They open in the evening, hence the name "evening primrose", and close by the following noon. The flower has a bright nectar guide pattern, invisible in visible light, but apparent under ultraviolet light, which assists its pollinators: Lepidoptera (moths and butterflies) and bees. The fruit is a capsule 2–4 cm long and 4–6 mm broad, containing numerous 1–2 mm long seeds, released when the capsule splits into four sections at maturity.^[2][3][4][5]

Synonym

It is also known as Weedy evening-primrose, German rampion, hog weed, King's cure-all, and fever-plant.^[6]

Cultivation and uses

The mature seeds contain approximately 7-10% gamma-linolenic acid, a rare essential fatty acid. The O. biennis seed oil is used to reduce the pains of premenstrual stress syndrome and is beneficial to the skin of the face. Also, poultices containing O. biennis were at one time used to ease bruises and speed wound healing.

References

From Wikispecies

Oenothera biennis

Taxonavigation

Classification System: APG II (down to family level)

Main Page
Cladus: Eukaryota
Regnum: Plantae
Cladus: Angiospermae
Cladus: Eudicots
Cladus: core eudicots
Cladus: Rosids
Cladus: Eurosids I
Ordines: Unassigned Eurosids I
Cladus: Unassigned Rosids
Ordo: Myrtales
Familia: Onagraceae
Subfamilia: Onagroideae
Tribus: Onagreae
Genus: Oenothera
Species: Oenothera biennis

Name

Oenothera biennis L.

Synonyms

• Oenothera muricata L.
• Oenothera suaveolens Desfontaines
• Onagra biennis (L.) Scopoli
• Onagra muricata (L.) Moench

References

• Species Plantarum 1:346. 1753
• USDA, ARS, National Genetic Resources Program. Germplasm Resources Information Network - (GRIN) [Online Database]. [1]

Vernacular name

For more multimedia, look at Oenothera biennis on Wikimedia Commons.