Oenothera capillifolia |
Oenothera cavernae |
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cave evening-primrose, cavedwelling evening primrose |
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Habit | Herbs perennial (short-lived or, sometimes, suffrutescent) or annual, glabrous or strigillose; from a stout taproot. | Herbs winter or spring annual, acaulescent or short-caulescent, glandular puberulent, sometimes also sparsely hirsute; from a taproot. | ||||
Stems | 1–many, weakly decumbent to ascending or erect, unbranched to moderately branched, (10–)25–80 cm. |
(when present) 1–several, ascending, usually unbranched, 2–4 cm. |
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Leaves | 1–9 × (0.1–)0.3–1 cm, sometimes fascicles of small leaves to 2 cm present in non-flowering axils; petiole 0–0.6 cm; blade linear to narrowly lanceolate or oblanceolate, often folded lengthwise, usually not much reduced distally, proximalmost leaves sometimes spatulate, base attenuate, margins subentire or serrulate or spinulose-serrate, apex acute. |
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. |
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Flowers | opening at sunrise; buds with free tips 0–4 mm; floral tube 5–20 mm; sepals 4–12 mm, midribs keeled; petals yellow, fading orangish to purplish, 6–25 mm; antisepalous filaments 2–8 mm, antipetalous filaments 1–4 mm, anthers 2–7 mm, pollen 90–100% fertile; style 9–30 mm, stigma sometimes blue-black, discoid to quadrangular, exserted beyond anthers. |
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. |
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Capsules | 10–35 × 1–2 mm, hard, dehiscent 1/2 their length, often tardily dehiscent throughout their length. |
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. |
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Seeds | obovoid, 1–1.8 mm, sharply angled, apex truncate. |
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. |
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2n | = 14. |
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Oenothera capillifolia |
Oenothera cavernae |
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Phenology | 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. | |||||
Elevation | 400–1700 m. (1300–5600 ft.) | |||||
Distribution | c United States; sc United States; n Mexico |
AZ; CA; NV |
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Discussion | Subspecies 2 (2 in the flora). Oenothera capillifolia is self-incompatible (H. F. Towner 1977). Oenothera berlandieri (Spach) Steudel 1841, not D. Dietrich 1840, is superfluous and cannot be used in Oenothera when transferred from Calylophus, and pertains here. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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.) |
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Key |
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Source | FNA vol. 10. | FNA vol. 10. | ||||
Parent taxa | Onagraceae > subfam. Onagroideae > tribe Onagreae > Oenothera > sect. Calylophus > subsect. Calylophus | Onagraceae > subfam. Onagroideae > tribe Onagreae > Oenothera > sect. Pachylophus | ||||
Sibling taxa | ||||||
Subordinate taxa | ||||||
Synonyms | Meriolix capillifolia | |||||
Name authority | Scheele: Linnaea 21: 576. (1848) | Munz: Leafl. W. Bot. 3: 50. (1941) | ||||
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