Flaming Gorge Evening Primrose

Oenothera acutissima

Native to:
United States

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Taxonomy

Division:
Magnoliophyta | - Flowering plants
Family:
Onagraceae
Genus:
Oenothera
Species:
Oenothera acutissima
USDA Symbol:
OEAC

Growth Characteristics

Life Cycle:
Perennial
Growth Habit:
Forb/herb
Height:
60 cm
Light Requirements:
Full Sun
Drought Tolerance:
Medium
Bloom Months:
jun,jul,aug,sep
Bloom Colors:
yellow

Wildlife Benefits

Bees:
★☆☆☆☆ Documented bee visitation (GBIF)

Keystone Species Ranking

Caterpillar Keystone:
★★☆☆☆ Butterfly & moth species supported by this genus (NWF)
Pollen Specialist Bee Keystone:
★★★☆☆ Native pollen specialist bee species supported by this genus (NWF)

Garden & Ecology Notes

Wildlife Value:
bees, moths
Fragrant:
Yes

Soil Requirements

Soil Type:
sandy, well-drained, nutrient-poor soil
pH:
6.0 - 7.5 (slightly acidic to neutral)
Drainage:
excellent drainage required
Moisture:
dry to moderate
Notes:
native to rocky slopes and open areas

Propagation & Germination

Stratification:
Cold/moist stratification required — 30–60 days
Germination Time:
14–30 days
Notes:
Seeds may germinate without stratification but cold treatment improves rates. Light may enhance germination.

The above propagation data sourced from Claude AI

Pre-treatment: Cold-moist stratification for 30 days at 1–5°C (34–41°F).

Notes: Light required for germination; do not cover seed.

Source: Claude AI