Oenothera organensis
Oenothera grandiflora
Organ Mountain evening primrose
large-flower evening-primrose
weakly erect to ascending, many from base, forming clumps 1–1.5 m diam., often branched distally, 30–60 cm.
erect, red on proximal parts, usually green on distal ones, rarely red throughout, unbranched or with branches obliquely arising from rosette and secondary branches arising from main stem, 100–300(–400) cm.
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.
in a basal rosette and cauline, basal 18–32 × (2–)3–6.5 cm, cauline 6–20 × 1.5–6.5 cm;
blade soft and thin, bright green, usually flat, rarely undulate, narrowly oblanceolate to narrowly obovate, or narrowly elliptic to elliptic, sometimes narrowly ovate distally, margins bluntly dentate or subentire, teeth widely spaced, sometimes sinuate-dentate proximally or lobed;
bracts usually caducous.
erect, often with secondary or tertiary branches just proximal to main one.
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.
opening near sunset;
buds erect, 5–9 mm diam., with free tips terminal, erect, 2–9 mm;
floral tube 35–55 mm;
sepals yellowish green or flushed with red, 22–46 mm;
petals yellow to pale yellow, fading pale yellowish white, very broadly obcordate or obovate, (25–)30–45 mm;
filaments 18–27 mm, anthers 10–15 mm, pollen 90–100% fertile;
style 57–90 mm, stigma exserted beyond anthers at anthesis.
erect to slightly spreading at acute angle from stem, cylindrical, 25–35 ×4–5.5 mm, dehiscent at least 3/4 their length.
erect or slightly spreading, dull green when dry, narrowly lanceoloid to narrowly ovoid, 15–35 × 3.5–5.5 mm, free tips of valves 0.5–2.5 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.
1–1.7 × 0.6–1.2 mm.
= 14.
= 14.
Oenothera organensis
Oenothera grandiflora
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.)
Oenothera grandiflora has a scattered distribution, from the eastern half of Mississippi and Alabama, east to Tennessee (Franklin and Marion counties), North Carolina (Cherokee, Macon, Martin, Moore, New Hanover, Sampson, and Swain counties), South Carolina (Oconee, Spartanburg, and Sumter counties), and Florida (Alachua, Escambia, Franklin, Lake, Leon, Polk, Putnam, and Santa Rosa counties). Collections from southern Canada, New York, Pennsylvania, Vermont, and West Virginia almost certainly represent cultivated plants, garden escapes, or adventive populations, and the single locality from central Kentucky also may be an introduction; it is sometimes a colonizer in disturbed sites such as along roads.
Oenothera grandiflora has plastome III and a BB genome composition. As summarized by W. Dietrich et al. (1997), some populations of O. grandiflora seem to be entirely or mostly composed of self-incompatible individuals, whereas others consist of self-compatible plants. This is an extremely uncommon phenomenon within a single species of Oenothera; the only other species known to exhibit mixed populations of self-incompatible and self-compatible individuals is O. primiveris.
Oenothera grandiflora Lamarck 1798, being a later homonym of O. grandiflora L’Héritier 1789, pertains here.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
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