Scientific Family
Onagraceae
Synonyms
Anogra albicaulis, Oenothera ctenophylla
Other common names
white-stem evening-primrose
pale evening-primrose
prairie evening primrose
halfshrub sundrop
Plant type
Forbs and Subshrubs
Origin
Native
Lifecycle
Annual
Height
1 to 1-1/2 feet
Riparian
No
Roundish gray-green plant with showy white flowers. Flowers can fade to pale pink as they age.
Hypanthium tube (cup-shaped extension of floral parts) without long hairs in the throat; petals 1/2 to 1-1/2 inches long. Flowers white; buds nodding. Seeds in 2 rows in each cell, with shallow pits in regular rows.
Habitat
Dry, grassy, sandy or disturbed areas.
Plant Community
Pinyon Juniper Woodlands
Montane Conifer Forest
Interior Chaparral
Grasslands
Disturbed Areas
Desert Scrub
Low elevation
2500
High elevation
7500
Flower Characteristics
Flowers are made up of four white, heart-shaped petals, to 1-1/2 inches wide. Flowers open near sunset and remain open for several days. The petals are white when fresh and the stamens are of equal length. Flowers arise individually from upper leaf axils.
Flower color
White
Flower shape
Regular
Tubular
No
First bloom month
March
Last bloom month
August
Flower clusters
None
Leaf and Stem Characteristics
The basal leaves grow to 2 inches in length with variable shapes and may have smooth or lobed edges. The leaves growing from the stems are long and thin. The hairs on the stems give a whitish appearance.
Leaf type
Simple
Leaf color
Grayish-green
Leaf shape
Pinnatifid
Leaf margin
Lobed
Leaves clasp
No
Leaf hairs
Leaves & stems
Spines
No
Fruit and Seed Characteristics
The fruits are cylindrical capsules containing many seeds.
Fruit type
Capsule
Fruit color
Yellowish-brown
Seeds ellipsoid, yellowish-brown, pitted, in 2 rows in each compartment.