Oenothera heterophylla
Oenothera villosa
variableleaf evening primrose
hairy evening-primrose, villous evening primrose, yellow evening-primrose
unbranched or branched mainly in distal part, 25–70 cm.
erect, usually flushed with red proximally, sometimes green or red throughout, unbranched or with branches obliquely arising from rosette and secondary branches arising from main stem, 50–200 cm.
in a basal rosette and cauline, basal 7–15 × 1–2.5 cm, cauline 3–13 ×0.4–2.3 cm;
blade narrowly oblanceolate to oblanceolate, gradually narrowly lanceolate to lanceolate or elliptic distally, margins deeply lobed to remotely dentate or subentire;
bracts longer than capsule they subtend, 1–3 cm.
in a basal rosette and cauline, basal 10–30 × 1.2–4(–5) cm, cauline 5–20 × 1–2.5(–4) cm;
blade dull green or grayish green, narrowly oblanceolate, oblanceolate to narrowly elliptic, or narrowly lanceolate, margins flat or undulate, dentate to subentire, teeth sometimes widely spaced, sometimes sinuate-dentate proximally;
bracts persistent.
dense, often with several lateral branches, mature buds usually overtopping spike apex.
dense to open, erect, unbranched.
2–several per spike opening per day near sunset;
buds erect, with free tips erect or spreading, 1–6 mm;
floral tube nearly straight, 25–47 mm;
sepals 15–30 mm;
petals yellow, broadly elliptic to nearly rhombic, 18–35 mm;
filaments 15–30 mm, anthers 3–8 mm, pollen 85–100% fertile;
style 45–75 mm, stigma usually exserted beyond anthers at anthesis.
opening near sunset;
buds erect, 3–5 mm diam., with free tips terminal, erect, 0.5–3 mm;
floral tube 23–44 mm;
sepals green to yellowish green, red-striped, or flushed with red, 9–18 mm;
petals yellow to pale yellow, fading orange or pale yellow, very broadly obcordate, 7–20 mm;
filaments 7–15 mm, anthers 4–10 mm, pollen ca. 50% fertile;
style 30–55 mm, stigma surrounded by anthers at anthesis.
lanceoloid, 13–25 × 2.5–4 mm.
erect or slightly spreading, dull green or gray-green when dry, lanceoloid, 20–43 × 4–7 mm, free tips of valves 1–2 mm.
brown, often flecked with darker spots, ellipsoid to broadly ellipsoid, 1.1–1.8 × 0.4–0.8 mm.
1–2 × 0.5–1.2 mm.
Oenothera heterophylla
Oenothera villosa
Subspecies 2 (2 in the flora).
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Subspecies 2 (2 in the flora).
Oenothera villosa is a PTH species and forms a ring of 14 chromosomes in meiosis, and is self-compatible and autogamous with plastome I and a AA genome composition (W. Dietrich et al. 1997). The original natural range of O. villosa was presumably from southern British Columbia south to California and east through the Rocky Mountain and the Great Plains regions. The wide occurrence east of this area in North America to eastern Quebec south throughout most of the eastern half of the United States, except for extreme southern and southeastern parts, is most likely the result of recent spread of this species, probably in the past several hundred years. Oenothera villosa is subdivided into two subspecies: subsp. strigosa occurs primarily in the Pacific Northwest southeast through the Rocky Mountains; subsp. villosa is found primarily from the eastern foothills of the Rocky Mountains eastward throughout the Great Plains region. Both taxa occur sporadically beyond these regions, and subsp. villosa is naturalized in many parts of the world.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
1. Herbs densely to sparsely strigillose, also at least parts of inflorescence sparsely hirsute with spreading, pustulate-based hairs, and often glandular puberulent and villous; flower buds with free tips spreading, 2–6 mm. | subsp. heterophylla |
1. Herbs densely to sparsely strigillose, also at least part of inflorescence glabrate or glandular puberulent; flower buds with free tips erect, 1–3 mm. | subsp. orientalis |
1. Inflorescences usually dense (internodes in fruit usually shorter than capsule); plants dull green to grayish green, densely strigillose and sometimes also sparsely villous with appressed or subappressed hairs, these without or with red or green pustulate bases, rarely sparsely glandular puberulent distally; sepals green to yellowish green; leaf blade margins conspicuously dentate, venation prominent, especially abaxially. | subsp. villosa |
1. Inflorescences usually open (internodes in fruit usually as long as or longer than capsule); plants flushed with red at least proximally, often red throughout, strigillose, usually also villous with erect to sometimes appressed hairs with pustulate bases, pustules red, also glandular puberulent at least distally; sepals red-striped or flushed with red; leaf blade margins usually denticulate or subentire, sometimes moderately dentate, venation not prominent. | subsp. strigosa |
CA
WildflowerSearch
iNaturalist
USDA Plants Database
BC
OR
Flora NW
PNW Herbaria
