Oenothera wolfii
Oenothera nutans
Wolf's evening-primrose
nodding evening-primrose
erect, green, flushed with red proximally or red throughout, unbranched or branches obliquely arising from rosette and sometimes secondary branches arising from main stem, 50–100 cm.
erect, red on proximal parts, green on distal ones, rarely red throughout, unbranched or with branches obliquely arising from rosette and secondary branches arising from main stem, 30–200 cm.
in a basal rosette and cauline, basal 13–35 ×1.5–4(–5) cm, cauline 5–18 × 1–2.5(–4) cm;
blade dull green, flat, oblanceolate to narrowly lanceolate or lanceolate to elliptic, margins bluntly dentate or subentire, teeth widely spaced or sinuate proximally;
bracts persistent.
in a basal rosette and cauline, basal 10–32 × 3–7 cm, cauline 6–20 × 2–8 cm;
blade green to pale green, narrowly oblanceolate to narrowly obovate, or narrowly elliptic, sometimes lanceolate distally, margins usually flat, rarely undulate, bluntly dentate, teeth widely spaced, sometimes sinuate-dentate proximally;
bracts caducous.
erect, unbranched.
erect, unbranched or with secondary branches just proximal to main one.
opening near sunset;
buds erect, 5–8 mmdiam., with free tips terminal, erect, 1–3 mm;
floral tube 30–46 mm;
sepals yellowish green, also usually flushed with red or red-striped, 17–28 mm;
petals yellow, fading orange, pale yellow and somewhat opaque, very broadly obcordate, 13–23 mm, conspicuously shorter than sepals;
filaments 12–20 mm, anthers 7–12 mm, pollen ca. 50% fertile;
style 43–58 mm, stigma usually slightly exserted beyond anthers or surrounded by them at anthesis.
opening near sunset;
buds erect, 4–6 mm diam., with free tips terminal, erect, 1.5–6 mm;
floral tube 30–43 mm;
sepals yellowish green or flushed with red, 10–23 mm;
petals yellow to pale yellow, fading pale yellowish white, very broadly obcordate, 14–25(–30) mm;
filaments 10–25 mm, anthers 4–10 mm, pollen ca. 50% fertile;
style 35–63 mm, stigma surrounded by anthers at anthesis.
erect or slightly spreading, dark dull green and sometimes red-striped when dry, narrowly lanceoloid, 30–48 × 5–7 mm, free tips of valves 0.5–2.5mm.
erect or slightly spreading, dull green when dry, narrowly lanceoloid to narrowly ovoid, 12–36 × 3–6 mm, free tips of valves 1–1.5 mm.
0.9–2 × 0.9–1.3 mm.
1–1.9 × 0.6–0.9 mm.
= 14.
= 14.
Oenothera wolfii
Oenothera nutans
Oenothera wolfii is a PTH species and forms a ring of 14 chromosomes in meiosis, and is self-compatible and autogamous (W. Dietrich et al. 1997). It has plastome I and a AA genome composition. It is known only from the vicinity of Port Orford, Curry County, Oregon (currently apparently only as far north as Otter Rock), south in a scattered distribution through Del Norte County to the mouth of the Mattole River, Humboldt County, California. The distribution, at least in California, is closely associated with small patches of Cenozoic-age marine sediments, isolated from each other by Franciscan sedimentary and metamorphic rocks. Most populations appear to occur near river mouths or to the south of a headland. The largest populations center in the area about 11 km long in the vicinity of Crescent City in Del Norte County, between Point George and Enderts Beach in Redwood National Park. There are collections from two inland California localities, one at the eastern border of Humboldt County, California (Willow Creek, Trinity River Valley), and the other at Carville, Trinity County, that may be O. wolfii. If so, they would presumably represent recent introductions and should be studied further. As summarized by Dietrich et al., O. wolfii is a rare endemic of coastal habitats and known from about 20 different sites. The total number of individuals of O. wolfii apparently fluctuates, with perhaps no more than about 5000 individuals total. It is threatened by any potential development and alteration of its habitat, presently by road maintenance and foot traffic. Another possibly more serious threat comes from the recent spread of O. glazioviana to this area. Oenothera glazioviana could swamp populations through hybridization and, perhaps, by direct competition.
Oenothera wolfii is in the Center for Plant Conservation’s National Collection of Endangered Plants.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Oenothera nutans is a PTH species and forms a ring of 14 chromosomes or a ring of 12 and 1 bivalent in meiosis, and is self-compatible and autogamous (W. Dietrich et al. 1997). It has plastome III and a BB genome composition. The disjunct occurrences of O. nutans in Arkansas and Missouri probably represent unintentional introductions by humans.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
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OR
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USDA Plants Database
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MD Biodiversity
MI Flora
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