Oenothera cavernae |
Oenothera havardii |
|
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cave evening-primrose, cavedwelling evening primrose |
Havard's evening primrose |
|
Habit | Herbs winter or spring annual, acaulescent or short-caulescent, glandular puberulent, sometimes also sparsely hirsute; from a taproot. | Herbs compact to sprawling, strigillose; from a taproot, lateral roots producing adventitious shoots. |
Stems | (when present) 1–several, ascending, usually unbranched, 2–4 cm. |
usually many-branched, sometimes unbranched, often twining among vegetation, sometimes rooting at nodes, 5–25(–70) 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 usually quickly deciduous, (1–)2–5 × (0.2–)0.5–1.5 cm; petiole 0–0.6 cm; blade oblanceolate, linear-lanceolate to linear distally, margins few toothed to pinnately lobed to sinuate-dentate distally. |
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. |
1–few opening per day near sunset; buds often twisted, free tips coherent; floral tube (37–)45–60(–65) mm; sepals (16–)18–26(–30) mm; petals lemon-yellow, fading orange-red to reddish purple, usually elliptic, sometimes oblanceolate, (18–)21–30(–32) mm; filaments 15–18(–22) mm, anthers red, 6–13 mm; style (55–)65–86(–94) mm, stigma exserted beyond anthers at anthesis. |
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. |
woody, narrowly ovoid to ovoid, 4-angled, 8–13(–16) × 3–4 mm, apex tapering to a short sterile beak 2–3 mm, valves with a prominent, broad midrib and capsule appearing 8-ribbed, tardily dehiscent ca. 1/3 capsule length. |
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. |
2–2.5(–3.3) × 1.2–1.5 mm, sometimes with a small wing at distal end or a raised ridge along one longitudinal margin. |
2n | = 14. |
= 14, 28. |
Oenothera cavernae |
Oenothera havardii |
|
Phenology | Flowering Mar–May. | Flowering Apr–Oct. |
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. | In depressions, seasonally wet flats, stream banks, margins of irrigated fields, sandy or clay soil, among tufted grasses like Sporobolus wrightii, primarily in Chihuahuan Desert. |
Elevation | 400–1700 m. (1300–5600 ft.) | 1300–2000 m. (4300–6600 ft.) |
Distribution |
AZ; CA; NV |
AZ; TX; Mexico (Chihuahua, Durango, Sonora, Zacatecas) |
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.) |
Oenothera havardii ranges from Brewster and Presidio counties, Texas, and Cochise County, Arizona, south to Durango and Zacatecas, Mexico. W. L. Wagner (1984) found that O. havardii is self-incompatible and vespertine. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 10. | FNA vol. 10. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | Hartmannia havardii, H. palmeri | |
Name authority | Munz: Leafl. W. Bot. 3: 50. (1941) | S. Watson: Proc. Amer. Acad. Arts 20: 366. (1885) — (as havardi) |
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