Oenothera texensis |
Oenothera pilosella |
|
---|---|---|
Texas evening primrose |
meadow evening-primrose |
|
Habit | Herbs perennial, caulescent, strigillose and also sparsely hirsute; from slender taproot. | Herbs perennial, usually densely to sparsely hirsute, rarely glabrous; from a thickened base, rhizomatous. |
Stems | several–many, ascending, unbranched or branched, 25–50 cm. |
spreading or ascending, unbranched or few-branched distally, 20–80 cm. |
Leaves | in a basal rosette and cauline, basal (1–)2.5–6.5 × 0.6–2.3 cm, blade narrowly elliptic to narrowly ovate or ovate, margins weakly serrulate to sinuate-pinnatifid; cauline 1–5.5 × 0.6–2 cm, blade narrowly elliptic to narrowly ovate, margins weakly serrulate. |
in a basal rosette and cauline, basal 4–8 × 2–5 cm, petiole (0.5–)1–3(–4) cm, blade oblanceolate to ovate, margins entire; cauline 3–10(–13) × 1–2(–4) cm, petiole 0–0.5(–2) cm, blade lanceolate to ovate, abruptly narrowed to base, margins subentire or coarsely dentate. |
Inflorescences | erect. |
erect, flowers in axils of distalmost few nodes. |
Flowers | 1–3 opening per day near sunrise; buds with free tips 0–1 mm; floral tube 15–26 mm; sepals 15–23 mm; petals rose purple, fading darker, 12–25(–30) mm; filaments 9–13 mm, anthers 3.5–6mm, pollen 85–100% fertile; style 26–36 mm, stigma exserted beyond anthers at anthesis. |
opening near sunrise; buds with free tips 1–3 mm, spreading; floral tube 10–25 mm; sepals 10–20 mm; petals bright yellow, fading pale pink or pale yellow, 15–30 mm; filaments 7–15 mm, anthers 4–8 mm, pollen 85–100% fertile; style 10–20 mm, stigma exserted beyond anthers at anthesis. |
Capsules | clavate or narrowly obovoid, 9–15 × 3.5–6 mm, apex attenuate to a sterile beak, valve midrib prominent in distal part, proximal stipe 7–12(–28) mm, gradually taperingto base; sessile. |
usually oblong-clavate to oblong-ellipsoid or ellipsoid, 4-angled or weakly 4-winged, (5–)10–15(–28) × 2–4(–5) mm, stipe (1–)3–5(–9) mm; sessile. |
Seeds | narrowly obovoid, 0.8–1 × 0.2–0.4 mm. |
1 × 0.5 mm. |
2n | = 14. |
= 56. |
Oenothera texensis |
Oenothera pilosella |
|
Phenology | Flowering May–Sep. | Flowering May–Jul(–Aug). |
Habitat | Sandy and gravel bars of streambeds and along streams. | Open fields, edge of woods, marshes and bottomland prairies, open disturbed sites, ditches, old fields, railroads, roadsides. |
Elevation | 900–2500 m. (3000–8200 ft.) | 100–600 m. (300–2000 ft.) |
Distribution |
TX; Mexico (Coahuila, Tamaulipas) |
AL; AR; CT; IA; IL; IN; KY; LA; MA; ME; MI; MO; MS; NH; NY; OH; OK; PA; RI; VA; VT; WI; WV; ON
|
Discussion | In the flora area, Oenothera texensis is known only from Jeff Davis County. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Oenothera pilosella is widespread in cultivation in gardens and frequently escapes and becomes naturalized; the northern and eastern natural limits of O. pilosella are not clear. According to G. B. Straley (1977) the natural limits are from Wayne County, West Virginia, along the Ohio River and Erie County, New York, for the eastern limits, and Tuscola County, Michigan, and Manitowoc County, Wisconsin, for the northern limits. K. N. Krakos (2014), based on new field studies and phylogenetic data, found that O. pilosella does not form a monophyletic group with plants previously treated by Straley as O. pilosella subsp. sessilis in molecular analyses, and thus is here reinstated as the distinct species O. sessilis. Straley determined that O. pilosella is self-incompatible and an octoploid, one of the few in the genus. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 10. | FNA vol. 10. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | Kneiffia fruticosa var. pilosella, K. pilosella, K. pratensis, K. sumstinei, O. fruticosa var. hirsuta, O. fruticosa var. pilosella, O. pratensis | |
Name authority | P. H. Raven & D. R. Parnell: Madroño 20: 247. (1970) | Rafinesque: Ann. Nat. 1: 15. (1820) |
Web links |