Oenothera pilosella |
Oenothera boquillensis |
|
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meadow evening-primrose |
Rio Grande beeblossom |
|
Habit | Herbs perennial, usually densely to sparsely hirsute, rarely glabrous; from a thickened base, rhizomatous. | Herbs perennial, strigillose and glandular puberulent; from a narrow taproot. |
Stems | spreading or ascending, unbranched or few-branched distally, 20–80 cm. |
erect, usually branched several cm belowground or near base, sometimes also branched distally, 25–100 cm. |
Leaves | 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. |
in a basal rosette and cauline, basal 1–6.5(–13) × 0.4–1.5 cm, blade narrowly oblanceolate; cauline 0.5–3(–6.5) × 0.1–1.1 cm, blade very narrowly elliptic, narrowly lanceolate, or linear, margins sinuate-dentate to subentire. |
Inflorescences | erect, flowers in axils of distalmost few nodes. |
|
Flowers | 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. |
4-merous, slightly zygomorphic, opening near sunset; floral tube 3–8.5 mm; sepals 3–9 mm; petals white, fading pink to red, slightly unequal, elliptic-obovate, 4–10 mm, clawed; filaments 2–4.5 mm, anthers 2–4 mm, pollen 85–100% fertile; style 6.5–15 mm, stigma exserted beyond anthers at anthesis. |
Capsules | 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. |
erect, sometimes reflexed in age, fusiform, sometimes slightly narrowed in proximal 1/3, 5.5–13 × 1–2.5 mm, valves with inconspicuous raised midrib; sessile. |
Seeds | 1 × 0.5 mm. |
(1 or)2–4, yellowish or light brown, 1.5–2.5 × 0.8–1.3 mm. |
2n | = 56. |
= 14. |
Oenothera pilosella |
Oenothera boquillensis |
|
Phenology | Flowering May–Jul(–Aug). | Flowering May–Aug. |
Habitat | Open fields, edge of woods, marshes and bottomland prairies, open disturbed sites, ditches, old fields, railroads, roadsides. | Washes, sandy canyon sides. |
Elevation | 100–600 m. (300–2000 ft.) | 600–1400 m. (2000–4600 ft.) |
Distribution |
AL; AR; CT; IA; IL; IN; KY; LA; MA; ME; MI; MO; MS; NH; NY; OH; OK; PA; RI; VA; VT; WI; WV; ON
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TX; Mexico (Chihuahua, Coahuila, Nuevo León) |
Discussion | 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.) |
Oenothera boquillensis has a narrow distribution in canyons from near the Rio Grande River in southern Brewster County southward into Mexico from central Chihuahua, Coahuila, and western Nuevo León. P. H. Raven and D. P. Gregory (1972[1973]) determined O. boquillensis to be self-incompatible. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 10. | FNA vol. 10. |
Parent taxa | Onagraceae > subfam. Onagroideae > tribe Onagreae > Oenothera > sect. Kneiffia | Onagraceae > subfam. Onagroideae > tribe Onagreae > Oenothera > sect. Gaura > subsect. Campogaura |
Sibling taxa | ||
Synonyms | Kneiffia fruticosa var. pilosella, K. pilosella, K. pratensis, K. sumstinei, O. fruticosa var. hirsuta, O. fruticosa var. pilosella, O. pratensis | Gaura boquillensis |
Name authority | Rafinesque: Ann. Nat. 1: 15. (1820) | (P. H. Raven & D. P. Gregory) W. L. Wagner & Hoch: Syst. Bot. Monogr. 83: 211. (2007) |
Web links |