Oenothera argillicola
Oenothera wolfii
shale barren evening primrose
Wolf's evening-primrose
erect to ascending, green or red, unbranched or with branches obliquely arising from rosette or in distal 1/2 of main stem.
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.
in a basal rosette and cauline, basal 7–25 × 0.7–2 cm, cauline 6–13 × 0.4–1 cm;
blade dark green, somewhat glossy, very narrowly oblanceolate to narrowly oblanceolate, linear-elliptic, lanceolate, or nearly linear, margins flat, entire or remotely and bluntly dentate, sometimes with larger teeth near base;
bracts persistent.
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.
curved with ascending tip, unbranched.
erect, unbranched.
opening near sunset;
buds erect, 4–8 mm diam., with free tips subterminal, divergent and hornlike, 3–9 mm;
floral tube 32–52 mm;
sepals yellowish green to yellow, sometimes flushed with red, especially at apex, 27–38 mm;
petals yellow to pale yellow, fading pale yellow to pale yellowish orange, very broadly obcordate or obovate, 25–42 mm;
filaments 20–27 mm, anthers 9–13 mm, pollen 90–100% fertile;
style 60–85 mm, stigma exserted beyond anthers at anthesis.
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.
spreading at nearly a right angle to stem, curved upward, sometimes secund, dull green or rusty brown when dry, narrowly lanceoloid to lanceoloid, 20–40 × 4–6 mm, free tips of valves 1–2 mm.
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.
1.3–1.9 × 0.7–1.1 mm.
0.9–2 × 0.9–1.3 mm.
= 14.
= 14.
Oenothera argillicola
Oenothera wolfii
Oenothera argillicola is one of eight angiosperm species restricted to the Devonian Brallier shale barrens, but among them only O. argillicola and Trifolium virginicum occur throughout the shale barren region. Oenothera argillicola has plastome V and a CC genome composition.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
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.)
MD Biodiversity
WildflowerSearch
iNaturalist
USDA Plants Database
CA
OR
Flora NW
PNW Herbaria
