Oenothera albicaulis aka Whitest Evening Primrose

Oenothera albicaulis bears the common name whitest evening primrose. It belongs to the evening primrose family, Onagraceae. Its native range spans west-central United States and northern Mexico. Kew includes Sonora and Chihuahua within its Mexican range. It grows in temperate regions and is not native to Britain or Ireland. Wild plants occur in dry grassland and disturbed ground.

Plants For A Future gives a height of 1 foot [0.3 metres]. Sources differ on how long the plant lives. Plants For A Future describes an annual or biennial. Kew records it as a perennial. The supplied species evidence gives no spread or leaf details. It also gives no clear account of stems or bark. These gaps limit a fuller account of its form.

Plants For A Future lists June as the flowering month. The blooms open in the evening and have a strong scent. They draw moths, while bees and butterflies also pollinate them. Each flower has both male and female parts. The plant is self-fertile, so it can set seed without another plant. Its scent and insect visitors give it value in wildlife planting. The evidence also lists it for use in cultivated beds.

Grow this plant in full sun rather than shade. It prefers sandy loam that drains well and stays fairly dry. It also accepts moist soil and soils low in nutrients. Suitable soils range from mildly acid to mildly alkaline. Heavy clay can lead to rot during winter. Plants For A Future lists USDA zones 4–8. Sow seed where plants will grow, in late spring or early summer. Autumn sowing is another option given by that source. The supplied evidence names no pests or other diseases.

Several parts have recorded food uses, though preparation matters. The leaves and young shoots are eaten cooked. Cooked seeds can go into soup or be ground for gravy. The small roots are also eaten cooked. Their reported best season runs from late autumn through early spring. They offer too little food to serve as a staple. Reports of edible fruit may refer to the seedpods. Plants For A Future records no known hazards, but this does not establish pet safety. It also records traditional treatments for swelling and muscle strains. These uses include plant poultices and root preparations, not evidence of proven medical benefit.