Oenothera calcicola

Herbs perennial, clumped, usually sparsely strigillose, rarely glabrate or sparsely villous, hairs erect, sometimes sparsely glandular puberulent distally; from twisted, woody rootstock. Stems erect, branched below and just above ground, branched also proximal to inflorescences, (40–)60–250 cm. Leaves in a basal rosette and cauline, basal 3–13 × 0.6–2.5 cm, blade spatulate to oblanceo­late, cauline (1–)2.5–12 × 0.1–1 cm, blade linear to narrowly oblanceolate, margins slightly to conspicuously sinuate-dentate. Inflorescences slender. Flowers 4-merous, zygomorphic, opening near sunset; floral tube 3–9 mm; sepals 6–12 mm; petals white, fading dark pink to red, slightly unequal, elliptic-obovate, 7–11 mm; stamens presented in lower 1/2 of flower, filaments 3–7 mm, anthers 2.5–5 mm, pollen 90–100% fertile; style 9.5–19 mm, stigma exserted beyond anthers at anthesis. Capsules lanceoloid to narrowly ovoid, narrowly 4-winged, 7–12 × 1.5–2.5 mm, tapered to a sterile stipe 2–5 mm. Seeds (2 or)3 or 4(or 5), light brown or reddish brown, 1.5–2.5 × 0.8–1.3 mm. 2n = 14.

Phenology: Flowering Apr–May.
Habitat: Dry limestone, gypsum, or caliche soil, slopes.
Elevation: 400–1800(–2100) m.

Distribution

• Generated Map
• Legacy Map

Tex., Mexico (Coahuila, Durango, Nuevo León, Tamaulipas).

Discussion

Oenothera calcicola occurs at mostly higher elevations and more montane areas than other species of subsect. Stipogaura, from the southern Trans-Pecos and Edwards Plateau regions of Texas southward into northern Mexico. P. H. Raven and D. P. Gregory (1972[1973]) determined O. calcicola to be self-incompatible. It is known to form hybrids with O. suffrutescens.

Selected References

None.

Lower Taxa

None.