Oenothera sessilis |
Oenothera suffulta |
|
---|---|---|
|
bee-blossom, kisses, roadside gaura, wild honey-suckle |
|
Habit | Herbs perennial, densely strigillose, glabrate proximally; from fibrous roots. | Herbs annual, sparsely villous proximally, leaves glabrate to sparsely villous along veins and on margins, usually glabrous distally, except sometimes proximal part of inflorescence, especially bracts, sparsely villous; from stout taproot. |
Stems | ascending, unbranched to few-branched, 30–65 cm. |
usually well-branched, 25–120 cm. |
Leaves | in a basal rosette and cauline, basal 2.5–7 ×0.7–2.3 cm, petiole 1–1.5 cm, blade oblanceolate, margins subentire, undulate; cauline (3–)6–7(–9) ×(0.3–)0.6–0.8(–1.1) cm, sessile, blade lanceolate to narrowly lanceolate, margins subentire. |
in a basal rosette and cauline, basal 7–11 × 0.1–2.3 cm, blade lyrate; cauline 1–9.5 × 0.1–2.3 cm, blade narrowly lanceolate to linear, margins sinuate-dentate, undulate. |
Inflorescences | nodding, flowers in axils of distalmost few nodes. |
|
Flowers | opening near sunrise; buds with free tips 1–2 mm, connivent to spreading; floral tube 10–15(–20) mm; sepals 10–18 mm; petals bright yellow, fading pale pink, 15–25 mm; filaments 7–9 mm, anthers 5–8 mm, pollen 85–100% fertile; style 10–12 mm, stigma exserted beyond anthers at anthesis. |
4-merous, zygomorphic, opening at sunset; floral tube 6.5–14 mm; sepals 11–21 mm; petals white, fading pink to red or sometimes purple, elliptic-obovate, 10–15 mm; filaments 6–9 mm, anthers 2–6 mm, pollen 90–100% fertile; style 16–32 mm, stigma exserted beyond anthers at anthesis. |
Capsules | ellipsoid, 4-angled, 8–10 × 3–4 mm, stipe 0–2 mm; sessile. |
ovoid, narrowly 4-winged, furrowed between angles, 4.5–8 × 2–5 mm, abruptly tapering to stipe 0–1 mm; sessile. |
Seeds | 1 × 0.5 mm. |
(1 or)2–4(or 5), yellowish to light brown, 2–3 × 1 mm. |
2n | = 56. |
= 14. |
Oenothera sessilis |
Oenothera suffulta |
|
Phenology | Flowering May–Jun. | Flowering Apr–Aug. |
Habitat | Moist remnant prairies in sandy or silty soil. | In open, sandy places. |
Elevation | 0–100 m. (0–300 ft.) | 10–1100 m. (0–3600 ft.) |
Distribution |
AR; LA; TX |
OK; TX
|
Discussion | Oenothera sessilis is relatively rare within its range and has a narrow overall distribution, occurring in Ashley, Phillips, Prairie, and St. Francis counties in Arkansas, Allen, Claiborne, and Tensas parishes in Louisiana, and Galveston County in Texas. Oenothera sessilis appears to be relatively rare and may no longer occur in Texas; it was last collected there in the 1840s by Lindheimer on Galveston Island. It is also rare in Louisiana but has been collected in recent decades. It is currently most common in Arkansas. P. A. Munz (1937, 1965) treated this taxon as O. sessilis, but G. B. Straley (1977) in his revision of sect. Kneiffia placed it as a subspecies of O. pilosella based on a common octoploid (2n = 56) chromosome number, morphology, and field studies. K. N. Krakos et al. (2014), based on new field studies, controlled greenhouse breeding experiments, and phylogenetic data found that this taxon differs morphologically from O. pilosella by having consistently shorter stature and smaller flowers, is self-compatible, and does not form a monophyletic group with O. pilosella in molecular analyses, and is here reinstated as a distinct species. Oenothera sessilis is in the Center for Plant Conservation’s National Collection of Endangered Plants as O. pilosella subsp. sessilis. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Oenothera suffulta is more common in western Texas while uncommon elsewhere throughout Texas, and absent in the Trans-Pecos region. P. H. Raven and D. P. Gregory (1972[1973]) determined O. suffulta to be self-incompatible. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 10. | FNA vol. 10. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | Kneiffia sessilis, O. pilosella subsp. sessilis, O. pilosella var. sessilis | Gaura suffulta |
Name authority | (Pennell) Munz: Bull. Torrey Bot. Club 64: 291. (1937) | (Engelmann ex A. Gray) W. L. Wagner & Hoch: Syst. Bot. Monogr. 83: 214. (2007) |
Web links |