Tufted Evening Primrose

Oenothera caespitosa

Taxonomy

Division:
Magnoliophyta | - Flowering plants
Family:
Onagraceae
Genus:
Oenothera
Species:
Oenothera caespitosa

Growth Characteristics

Life Cycle:
Perennial
Growth Habit:
Forb/herb , Subshrub
Height:
1-2 ft
Light Requirements:
Full Sun
Drought Tolerance:
High
Bloom Months:
apr, may, jun, jul, aug
Bloom Colors:
White
Ground Cover:
Yes

Native Range

United States: Arizona, California, Colorado, Idaho, Montana, North Dakota, Nebraska, New Mexico, Nevada, Oregon, South Dakota, Texas, Utah, Washington, Wyoming, Canada: Alberta, Manitoba, Saskatchewan

Keystone Species Ranking

Caterpillar Keystone:
★★★★☆ Based on number of butterfly and moth species using this genus as host plant (Source: National Wildlife Federation)
Bee Keystone:
★★★☆☆ Based on number of native bee species using this genus for pollen and nectar (Source: National Wildlife Federation)

Reported Fauna Sightings

Bees: Nevada bumble bee (Bombus nevadensis), Nevada bumble bee (Bombus nevadensis), Yellow bumble bee (Bombus fervidus), Yellow bumble bee (Bombus fervidus)

Soil Requirements

Soil Type:
gritty, well-drained, rocky soil
pH:
6.0 - 8.0 (neutral to slightly alkaline)
Drainage:
excellent drainage required
Moisture:
dry to moderate
Notes:
thrives in poor, low-nutrient soils

Germination Information

Pre-treatment: 5 month outdoor cold moist stratification

Establishment: Seeds are hand collected in late August when capsules turn dark brown and woody. Seeds are black at maturity. Capsules are collected using pruning shears and are stored in paper bags prior to cleaning.

Source: npn.rngr.net