Scientific Family
Onagraceae
Synonyms
Oenothera hookeri
Other common names
western eveningprimrose
Plant type
Forbs and Subshrubs
Origin
Native
Lifecycle
Biennial or perennial
Height
To 5 feet
Riparian
Yes
A tall, erect, usually unbranched stem with large, showy, yellow flowers clustered along the stem. The plant forms a basal rosette of leaves the first year. It sends up a long leafy stem and blooms during the second year.
Stems tall up to 5 feet, often red. Leaf flat, not crinkled. Petals yellow, 1 to 2 inches long, open late afternoon, aging orange-red. Tubes below the petals are 1 to 2 inches long. Fruit cylindrical, not winged; seeds sharply angeled.
Habitat
Found along streams, in meadows, rocky slopes or scree, or in other disturbed habitats.
Plant Community
Riparian
Disturbed Areas
Low elevation
3500
High elevation
9000
Flower Characteristics
Yellow flowers are up to 2 inches and consist of 4 broad, heart-shaped yellow petals; sepals up to 1/4 inch long, yellowish-green, red-striped or flushed. Flowers open in the late afternoon, becoming orange-red the following day, closing by noon.
Flower color
Yellow, orange-red
Flower shape
Regular
Tubular
Yes
First bloom month
July
Last bloom month
October
Flower clusters
Elongated
Leaf and Stem Characteristics
Dull to gray-green, white veined, lance-shaped, 1-1/2 to 9 inches long, up to 3/4 inch wide, narrower at the stem, margin toothed to almost smooth, sparse to dense stiff hairs. First year leaves form a rosette 4 to 16 inches long, to 1-1/2 inches wide.
Leaf type
Simple
Leaf color
Dull green to grayish-green
Leaf shape
Narrow
Leaf margin
Toothed
Leaves clasp
No
Leaf hairs
Leaves & stems
Spines
No
Fruit and Seed Characteristics
Capsules 3/4 to 2-1/2 inches long, tapering upward, narrowly lance-shaped. They start out green turning to tan.
Fruit type
Capsule
Fruit color
Tan
Seeds are pitted, reddish-brown in 2 rows in each cell.