Oenothera harringtonii

Herbs robust spring annual or, rarely, surviving a second-year, caulescent, hirtellous, also glandular puberulent; from stout taproot. Stems ascending to erect, stout, unbranched or with lateral stems from basal rosette, densely leafy, 15–30 cm. Leaves 10–14 (–14.5) × 1.5–2.3 (–3) cm; petiole 4.3–6.6 cm; blade narrowly oblanceolate, margins irregularly and coarsely dentate, apex acute. Flowers usually 5–10 per stem opening per day near sunset, with heavy, sweet scent; buds erect; floral-tube 31–60 mm; sepals 17–26 mm; petals white, fading pale-pink, 20–26 mm; filaments 11–16 mm, anthers 8–11 mm; style 65–96 mm, stigma exserted beyond anthers at anthesis. Capsules straight, lanceoloid, obtusely 4-angled, (21–) 25–30 (–35) × (5–) 6–8 mm, tapering to a sterile beak 6–8 mm, dehiscent 1/2–2/3 their length, valve margins with 5–8 conspicuous, irregular tubercles, sometimes 2 or more coalesced into a sinuate ridge, also with conspicuous medial ridge throughout; pedicel 0.5–1 mm. Seeds numerous, usually in 2 distinct rows per locule, sometimes rows partially overlapping, narrowly obovoid, 2.1–2.3 × 1–1.3 mm, embryo slightly less than 1/2 seed volume, surface appearing finely striate but papillose under magnification; seed collar with membrane intact at maturity, membrane rarely splitting and separating from collar, margin entire. 2n = 14.

Phenology: Flowering May–Jun.
Habitat: On compacted, silty clay to looser rocky and sandy soil in open grassland.
Elevation: 1400–1900 m.

Colo.

Discussion

Oenothera harringtonii is known only from southeastern Colorado from western El Paso and eastern Fremont counties, southeast through Pueblo to Otero counties, and south to Las Animas County; it may also occur in adjacent Colfax and Union counties in New Mexico but has not been collected there. Oenothera harringtonii is self-incompatible (W. L. Wagner et al. 1985; Wagner 2005).

Selected References

None.

Lower Taxa