Oenothera glaucifolia |
Oenothera organensis |
|
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false gaura |
Organ Mountain evening primrose |
|
Habit | Herbs probably biennial, glabrous, becoming sparsely to densely glandular puberulent and short-villous distally, glaucous at least in proximal parts; from stout roots. | 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 | erect, branched or unbranched, 30–300 cm. |
weakly erect to ascending, many from base, forming clumps 1–1.5 m diam., often branched distally, 30–60 cm. |
Leaves | in a basal rosette and cauline, basal 3–7 × 0.5–2 cm, sessile, blade oblong to oblong-lanceolate, base usually ± auriculate, margins entire; cauline 3–8(–10) × 0.4–1.8 cm, blade lanceolate to oblong-lanceolate, gradually smaller, becoming linear-subulate distally. |
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. |
Inflorescences | long, wandlike, unbranched or branched. |
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Flowers | 4-merous, nearly actinomorphic, opening near sunrise; floral tube 6–17 mm; sepals 4–6 mm; petals white, fading off-white or tinged pink, slightly unequal, rhombic, 4–6 mm, abruptly clawed; filaments 5–8 mm, anthers 1.5–2 mm, pollen 85–100% fertile; style 6–10, stigma exserted beyond anthers at anthesis. |
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. |
Capsules | ovoid, 4-angled, somewhat flattened, 3–4 × 1.5–2.3 mm, valves with raised midrib and conspicuous lateral veins; sessile. |
erect to slightly spreading at acute angle from stem, cylindrical, 25–35 ×4–5.5 mm, dehiscent at least 3/4 their length. |
Seeds | 1, pale yellow, oblanceoloid, 2.4–2.6 × 1–1.5 mm. |
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. |
2n | = 14. |
= 14. |
Oenothera glaucifolia |
Oenothera organensis |
|
Phenology | Flowering May–Oct(–Nov). | Flowering Jun–Sep. |
Habitat | Rocky prairie slopes and outcrops or bluffs, along streams, roadsides, usuallyon limestone. | In larger rhyolite canyons, along water courses, in eroded basins filled with gravel and rocks. |
Elevation | 200–1300 m. (700–4300 ft.) | 1800–2300 m. (5900–7500 ft.) |
Distribution |
AR; CO; KS; MO; NE; NM; OK; TX; WY
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NM |
Discussion | Oenothera glaucifolia is self-incompatible, the flowers diurnal, pollinated primarily by wasps (R. Clinebell, unpubl.), as well as bees, flies, butterflies, and occasionally beetles (summarized by W. L. Wagner et al. 2007). It was collected once in 1988 in Indiana at Miller Woods Visitor Center (Lake County), Dritz 596 (MOR); it seems likely that it was introduced, and has not been collected there since. Stenosiphon virgatus Spach is a superfluous name 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.) |
Source | FNA vol. 10. | FNA vol. 10. |
Parent taxa | Onagraceae > subfam. Onagroideae > tribe Onagreae > Oenothera > sect. Gaura > subsect. Stenosiphon | Onagraceae > subfam. Onagroideae > tribe Onagreae > Oenothera > sect. Oenothera > subsect. Emersonia |
Sibling taxa | ||
Synonyms | Gaura linifolia, Stenosiphon linifolius | O. macrosiphon |
Name authority | W. L. Wagner & Hoch: Syst. Bot. Monogr. 83: 212. (2007) | Munz ex S. Emerson: Genetics 23: 190. (1938) |
Web links |