Oenothera coronopifolia

Herbs perennial, strigillose, usually also hirsute; from a taproot, lateral roots producing adventitious shoots. Stems ascending to erect, 1–several from base, these unbranched to well-branched, 10–60 cm. Leaves in a weakly developed basal rosette and cauline, 2–7 × 0.2–1.5 cm, axillary fascicles of reduced leaves often present; blade oblanceolate to oblong, margins usually pinnatifid, sometimes proximal ones coarsely few-toothed. Flowers 1–3 opening per day near sunset; buds nodding, weakly quadrangular, without free tips; floral-tube 10–25 mm, mouth conspicuously pubescent, closed with straight, white hairs, 1–2 mm; sepals 10–20 mm; petals white, fading pink, ovate or shallowly obcordate, 10–15 (–20) mm; filaments 10–15 mm, anthers 4–7 mm; style 17–42 mm, stigma exserted beyond anthers at anthesis. Capsules ascending to erect, straight, fusiform, weakly 4-angled, 10–20 × 3–5 mm, dehiscent 1/2 their length; sessile. Seeds in 2 rows per locule, ellipsoid to subglobose, 1.5–2 × 1.2–1.5 mm, surface regularly pitted, pits in longitudinal lines. 2n = 14, 28.

Phenology: Flowering (Mar–)Jun–Aug(–Sep).
Habitat: Dry, open sites, grassy meadows, slopes, along drainages, foothills and mountains.
Elevation: 1500–3000 m.

Ariz., Colo., Idaho, Nebr., N.Mex., S.Dak., Utah, Wyo.

Discussion

Oenothera coronopifolia apparently has both self-incompatible and self-compatible populations (P. H. Raven 1979; W. L. Wagner et al. 2007; K. E. Theiss et al. 2010).

Selected References

None.

Lower Taxa