Oenothera cavernae |
Oenothera spachiana |
|
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cave evening-primrose, cavedwelling evening primrose |
spach's evening primrose |
|
Habit | Herbs winter or spring annual, acaulescent or short-caulescent, glandular puberulent, sometimes also sparsely hirsute; from a taproot. | Herbs annual, densely strigillose; from a sparsely branched taproot. |
Stems | (when present) 1–several, ascending, usually unbranched, 2–4 cm. |
erect, usually unbranched or with few ascending branches, 10–30(–45) cm. |
Leaves | primarily in a basal rosette, sometimes also cauline, (0.5–)2.5–13(–19.5) × (0.2–)0.6–2.3(–2.7) cm; petiole 0.5–5.2 cm; blade oblanceolate to elliptic-oblanceolate (in some exceptionally large leaves), margins lyrate-pinnatifid to subentire (in very small ones), apex usually rounded, rarely acute. |
in a basal rosette and cauline, basal 2–5 × 0.5–1.5 cm, petiole 0.5–2 cm, blade oblanceolate to elliptic, margins subentire; cauline 3–6 × 0.2–0.6 cm, petiole 0.2–0.6(–1.5) cm, blade narrowly lanceolate to linear, margins subentire. |
Inflorescences | erect, flowers in leaf axils in distal 1/2 of plant. |
|
Flowers | 1–3(–10) per stem opening per day near sunset, without noticeable scent; buds sometimes ± recurved before anthesis; floral tube (20–)30–37(–47) mm; sepals 4.5–12 mm; petals white, fading pale pink, (6.5–)8–20(–25) mm; filaments 5.2–7.5(–12) mm, anthers (1.4–)3–4.5(–6) mm; style (24–)35–45(–56) mm, stigma surrounded by anthers at anthesis. |
opening near sunrise; buds with free tips to 1 mm, erect to spreading; floral tube 4–10 mm; sepals 4–8 mm; petals pale yellow, fading pale pink, 5–14 mm; filaments 3–7 mm, anthers 2–4 mm, pollen 85–100% fertile; style 3–7 mm, stigma surrounded by anthers. |
Capsules | falcate (especially before maturity), ellipsoid-ovoid to ovoid, obtusely 4-angled, 12–38 × 6–14 mm, tapering to a sterile beak 2–8 mm, dehiscent to 1/2 their length, valve margins with a sinuate ridge or 8–20 nearly distinct tubercles; pedicel 0–10 mm. |
broadly clavate, 4-angled, 5–15 × 3–5 mm, stipe 2–5 mm; sessile. |
Seeds | usually numerous, sometimes as few as 5, in 2 adjacent rows per locule, obovoid, 2.5–3.1 × 1.1–1.4 mm, embryo 1/2 of seed volume, surface minutely papillose to reticulate; seed collar without membrane, producing a large empty cavity, margin irregularly sinuate. |
1 × 0.5 mm. |
2n | = 14. |
= 14. |
Oenothera cavernae |
Oenothera spachiana |
|
Phenology | Flowering Mar–May. | Flowering Mar–May. |
Habitat | Exposed calcareous slopes, crevices in limestone, dolomite, or loose talus, sandy arroyos, sandstone, granitic crevices, volcanic cinders in Mojave Desert or Great Basin scrub communities, rarely in arid juniper woodlands. | Prairies, open roadsides, sandy places. |
Elevation | 400–1700 m. (1300–5600 ft.) | 10–200 m. (0–700 ft.) |
Distribution |
AZ; CA; NV |
AL; AR; LA; MS; OK; TX |
Discussion | Oenothera cavernae is known from the Arrow Canyon, Las Vegas, and Sheep ranges and the low hills near Arden and Sloan in Clark County, Nevada, eastward along the Grand Canyon to the vicinity of Page, Arizona, and perhaps Washington County, Utah and formerly in Glenn Canyon, and more recently collected in eastern San Bernardino County, California (eastern Clark Mountain Range, and the base of range in Ivanpah Valley). W. L. Wagner et al. (1985) determined O. cavernae to be self-compatible and autogamous. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
G. B. Straley (1977) determined Oenothera spachiana to be self-compatible and autogamous. Collections outside the native range of O. spachiana have been made as a ballast weed in Camden County, New Jersey. Oenothera drummondii (Spach) Walpers (1843), not Hooker (1834) is a later homonym and pertains here. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 10. | FNA vol. 10. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | Blennoderma drummondii, Kneiffia spachiana, O. uncinata | |
Name authority | Munz: Leafl. W. Bot. 3: 50. (1941) | Torrey & A. Gray: Fl. N. Amer. 1: 498. (1840) |
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