Oenothera capillifolia |
Oenothera organensis |
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Organ Mountain evening primrose |
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Habit | Herbs perennial (short-lived or, sometimes, suffrutescent) or annual, glabrous or strigillose; from a stout taproot. | Herbs perennial, moderately hirsute (hairs often with reddish purple, pustulate bases), alsostrigillose and becoming glandular puberulent distally; initially from slender taproot with single rosette, later developing numerous adventitious shoots from taproot and lateral roots, root system then appearing fibrous. | ||||
Stems | 1–many, weakly decumbent to ascending or erect, unbranched to moderately branched, (10–)25–80 cm. |
weakly erect to ascending, many from base, forming clumps 1–1.5 m diam., often branched distally, 30–60 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. |
in a weakly developed basal rosette and cauline, basal 9–23 × 1–2.5 cm, cauline 5–11 × 1.5–3.5 cm; petiole 0.5–1.5 cm; blade very narrowly oblanceolate to narrowly elliptic, margins undulate, remotely and bluntly dentate. |
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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. |
opening near sunset, not strongly scented; buds with free tips terminal, erect, 3–10 mm; floral tube straight, 100–165(–190) mm; sepals 25–50 mm; petals yellow, fading deep reddish orange, broadly obovate with truncate apex, or obcordate, 30–55 mm; filaments 18–35 mm, anthers 10–19 mm; style 140–235 mm, stigma exserted beyond 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. |
erect to slightly spreading at acute angle from stem, cylindrical, 25–35 ×4–5.5 mm, dehiscent at least 3/4 their length. |
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Seeds | obovoid, 1–1.8 mm, sharply angled, apex truncate. |
numerous, in 2 distinct rows per locule, dark reddish brown, sometimes with darker flecks, obovoid, asymmetrical, irregularly angled, 1.5–2.1 × 1–1.2 mm, surface irregularly pitted and with collapsed papillae. |
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2n | = 14. |
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Oenothera capillifolia |
Oenothera organensis |
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Phenology | Flowering Jun–Sep. | |||||
Habitat | In larger rhyolite canyons, along water courses, in eroded basins filled with gravel and rocks. | |||||
Elevation | 1800–2300 m. (5900–7500 ft.) | |||||
Distribution | c United States; sc United States; n Mexico |
NM |
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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 organensis is known only from the Organ Mountains, Doña Ana County, especially on the east side. Various studies have been done to assess the status of this narrow endemic and estimate 2000 to 5000 individuals with wide fluctuations likely due to variation in rainfall (W. Dietrich et al. 1985). Oenothera organensis could decline if degradation of habitat increases in the Organ Mountains. The genetics and population biology of this taxon have been heavily studied in the past (summarized in Dietrich et al.). It is self-incompatible. (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. Oenothera > subsect. Emersonia | ||||
Sibling taxa | ||||||
Subordinate taxa | ||||||
Synonyms | Meriolix capillifolia | O. macrosiphon | ||||
Name authority | Scheele: Linnaea 21: 576. (1848) | Munz ex S. Emerson: Genetics 23: 190. (1938) | ||||
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