Scientific Family
Onagraceae
Synonyms
Oenothera amplexicaulis, O. laciniata ssp. pubescens, O. laciniata var. pubescens
Other common names
silky evening primrose
pubescent evening primrose
Plant type
Forbs and Subshrubs
Origin
Native
Lifecycle
Annual or perennial
Height
To about 30 inches
Riparian
Yes
Plant has long hairs on the stems, leaves and flower stalks mixed with shorter glandular hairs and stiff, flat hairs. Cross-shaped yellow flowers grow singly from the upper leaf axils (between the leaf and stem). Often 1 bloom opens per day near sunset.
Annual, perennial, basal rosettes of leaves and stem leaves, hairs long, glandular; flowers in leaf axils towards stem ends, yellow, stigmas with 4 narrow lobes, open late afternoon; buds nodding; fruit round in cross-section; seeds in 2 rows per cell.
Habitat
Open woodlands, pine forests, moist places, streambanks, disturbed areas.
Plant Community
Riparian
Pinyon Juniper Woodlands
Montane Conifer Forest
Disturbed Areas
Low elevation
3500
High elevation
9500
Flower Characteristics
Flower about 1-1/2 inches wide, 4 petals narrowing at base, forms a cross shape. Green leaf-like sepals are hairy, curve backward and are attached to a thin cup-shaped flower tube up to 2 inches long (hypanthium). Flower buds face downward.
Flower color
Yellow, ages pinkish-orange
Flower shape
Regular
Tubular
Yes
First bloom month
May
Last bloom month
October
Flower clusters
None
Leaf and Stem Characteristics
Leaves grow in a circular pattern (rosette) at the plant base and alternately on the stem. Leaves are narrow, often lance-shaped, up to 3 inches long, often lined with irregular points (teeth) but at times may have a smooth margin.
Leaf type
Simple
Leaf color
Green
Leaf shape
Narrow
Leaf margin
Toothed
Leaves clasp
No
Leaf hairs
Leaves & stems
Spines
No
Fruit and Seed Characteristics
The fruit is a green, elongated, cylinder-shaped, hairy capsule (round in cross-section) ranging from 1/2 to 1-1/2 inches long and 1/16 to 1/4 inch wide. Parallel lines or grooves run lengthwise around the surface of the fruit (striations).
Fruit type
Capsule
Fruit color
Green
Numerous seeds are produced by the fruit. Each seed is light brown, about 1/16 inch long with evenly distributed indentations on its surface (pitted) often giving it a flecked appearance.