Oenothera triangulata |
Oenothera mexicana |
|
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prairie beeblossom |
Mexican evening primrose |
|
Habit | Herbs annual, villous proximally, sparsely villous along veins and on margins, usually glabrate, sometimes strigillose distally; from taproot. | Herbs annual, moderately to sparsely strigillose and densely long-villous, sometimes also becoming glandular puberulent distally. |
Stems | ascending, usually well-branched from base and distally, rarely unbranched, 15–60 cm. |
erect to ascending, usually unbranched, or with arcuate lateral branches arising from rosette, 15–40(–60) cm. |
Leaves | in a basal rosette and cauline, 1.5–8 × 0.2–0.6(–1.5) cm, blade very narrowly elliptic to oblanceolate or oblong-elliptic, margins entire or weakly sinuate-dentate. |
in a basal rosette and cauline, basal 6–10 × 1–2.5 cm, cauline 3–7.5 × 0.8–2 cm; blade usually grayish green, narrowly oblanceolate to narrowly oblanceolate, margins deeply lobed, lobes usually dentate; bracts distalmost erect, revolute. |
Flowers | 3(or 4)-merous, zygomorphic, opening at sunset; floral tube 4–5.5 mm; sepals 4.5–6 mm; petals white, fading pink, elliptic-obovate, 3.5–5 mm; filaments 2–3.5 mm, anthers 1.5–3 mm, pollen 35–65% fertile; style 9–10 mm, stigma surrounded by anthers. |
usually 1 opening per day near sunset; buds erect, with free tips erect or appressed, 0.5–2.5 mm; floral tube 23–28 mm; sepals 5–12 mm; petals yellow, fading orange, broadly obovate or shallowly obcordate, 6–15 mm; filaments 4–12 mm, anthers 3–4 mm, pollen 85–100% fertile; style 27–40 mm, stigma surrounded by anthers at anthesis. |
Capsules | narrowly obovoid, 3(or 4)-winged, furrowed between wings, 7–9 × 3–5 mm, narrowed at base; sessile. |
cylindrical, sometimes slightly enlarged toward apex, 25–45 × 2.5–3 mm. |
Seeds | (1 or)2–5, yellowishto light brown, 1.5–3.5 × 1–1.5 mm. |
ellipsoid to subglobose, 0.8–1.2 × 0.3–0.5 mm. |
2n | = 14. |
= 14. |
Oenothera triangulata |
Oenothera mexicana |
|
Phenology | Flowering Apr–Jul. | Flowering Apr–May. |
Habitat | Open, sandy sites. | Open, sandy sites. |
Elevation | 200–600 m. (700–2000 ft.) | 30–200 m. (100–700 ft.) |
Distribution |
OK; TX |
TX |
Discussion | Oenothera triangulata is a PTH species and forms a ring of 14 chromosomes in meiosis. The species is self-compatible and autogamous (P. H. Raven and D. P. Gregory 1972[1973]). It may have been derived from hybridization between O. patriciae and O. suffulta. The species has a relatively narrow distribution across south-central Oklahoma and north-central Texas (Oklahoma in Cleveland, Comanche, Cotton, Grady, Oklahoma, Rogers, Stephens, and Tulsa counties; Texas in Archer, Baylor, Callahan, Clay, Coleman, Crosby, Eastland, Erath, Jones, Montague, Taylor, Throckmorton, Tom Greene, Wichita, Wilbarger, and Young counties). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Oenothera mexicana is known only from southeastern Texas (Atascosa, Aransas, Bexar, Brooks, Burleson, De Witt, Frio, Gonzales, Kenedy, Medina, Newton, Refugio, San Patricio, Waller, and Washington counties). It is self-compatible and autogamous, but not a PTH species. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 10. | FNA vol. 10. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | Gaura triangulata, G. hexandra var. triangulata, G. tripetala var. triangulata | O. laciniata var. mexicana, O. sinuata var. hirsuta, Raimannia mexicana |
Name authority | (Buckley) W. L. Wagner & Hoch: Syst. Bot. Monogr. 83: 214. (2007) | Spach: Nouv. Ann. Mus. Hist. Nat. 4: 347. (1836) |
Web links |