(Tufted Evening Primrose)
Oenothera cespitosa ssp. cespitosa, Pawnee Buttes, Weld Co. 7710
Oenothera cespitosa ssp. cespitosa, Pawnee Buttes, Weld Co. 7712
Oenothera cespitosa ssp. cespitosa, Pawnee Buttes, Weld Co. 7710
Oenothera cespitosa, Green Mountain Reservoir, Summit Co. 0097
Oenothera cespitosa, Green Mountain Reservoir, Summit Co. 0127
Oenothera cespitosa, Green Mountain Reservoir, Summit Co. 0108
Oenothera cespitosa, Green Mountain Reservoir, Summit Co. 0111
Oenothera cespitosa, Green Mountain Reservoir, Summit Co. 0121
| Scientific Name | Oenothera cespitosa ssp. cespitosa (Oenthera caespitosa ssp. caespitosa) | USDA PLANTS Symbol | OECAC2 |
| Common Name | Tufted Evening Primrose | ITIS Taxonomic Serial No. | 27383 |
| Family | Onagraceae (Evening Primrose) | SEINet Reference |
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| Description |
Life zones and habitat: Plains to montane (4600 to 10000 ft.); scattered or forming colonies in various types of dry soils and conditions: clay, sandy, shale, volcanic soils; flats, badlands, bluffs, exposed rocky ridges, roadcuts, grasslands, sagebrush and exposed sites in montane conifer forests.
Plant: Perennial growing in tufts, up to 12 inches tall, usually stemless; herbage with very short hairs. Leaves: Basal, petiolate leaves with lanceolate to elliptic blades, 4 to 10 inches long (including petiole) and 3/8 to 1-inch across; margins dentate or irregularly pinnatifid to entire. Inflorescence: Large, white, showy, solitary flower borne directly (usually) or on a short pedicel 1-1/4 inches long from among the leaves; floral tube is 1-5/8 to 2-3/8-inches long, petals fading to rose-pink or rose-purple; pink with age; greenish to reddish floral tube 1-1/2 to 5-1/5 inches long; 4 downward-pointing sepals 3/4 to 2 inches long; protruding style with 4-pronged stigma and 8 protruding white stamens; flowers open around sunset and wilt the next day. References: "Flora of Colorado" by Jennifer Ackerfield, SEINet, Flora of North America, UW Burke Herbarium and Washington State DNR. Note: There are several subspecies and the plants here from the Pawnee Buttes area of NE Colorado are most likely ssp. cespitosa and the ones fron Green Mountain Reservoir in Summit Co. could be the same or ssp. macroglottis. |
BONAP Distribution Map Map Color Key |
Colorado Status: Native |
© Tom Lebsack 2025
Banner photo: Castilleja rhexifolia and a brewing storm over the San Juan Mountains
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