Oenothera havardii |
Oenothera triangulata |
|
---|---|---|
Havard's evening primrose |
prairie beeblossom |
|
Habit | Herbs compact to sprawling, strigillose; from a taproot, lateral roots producing adventitious shoots. | Herbs annual, villous proximally, sparsely villous along veins and on margins, usually glabrate, sometimes strigillose distally; from taproot. |
Stems | usually many-branched, sometimes unbranched, often twining among vegetation, sometimes rooting at nodes, 5–25(–70) cm. |
ascending, usually well-branched from base and distally, rarely unbranched, 15–60 cm. |
Leaves | in a basal rosette and cauline, basal usually quickly deciduous, (1–)2–5 × (0.2–)0.5–1.5 cm; petiole 0–0.6 cm; blade oblanceolate, linear-lanceolate to linear distally, margins few toothed to pinnately lobed to sinuate-dentate distally. |
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. |
Flowers | 1–few opening per day near sunset; buds often twisted, free tips coherent; floral tube (37–)45–60(–65) mm; sepals (16–)18–26(–30) mm; petals lemon-yellow, fading orange-red to reddish purple, usually elliptic, sometimes oblanceolate, (18–)21–30(–32) mm; filaments 15–18(–22) mm, anthers red, 6–13 mm; style (55–)65–86(–94) mm, stigma exserted beyond anthers at anthesis. |
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. |
Capsules | woody, narrowly ovoid to ovoid, 4-angled, 8–13(–16) × 3–4 mm, apex tapering to a short sterile beak 2–3 mm, valves with a prominent, broad midrib and capsule appearing 8-ribbed, tardily dehiscent ca. 1/3 capsule length. |
narrowly obovoid, 3(or 4)-winged, furrowed between wings, 7–9 × 3–5 mm, narrowed at base; sessile. |
Seeds | 2–2.5(–3.3) × 1.2–1.5 mm, sometimes with a small wing at distal end or a raised ridge along one longitudinal margin. |
(1 or)2–5, yellowishto light brown, 1.5–3.5 × 1–1.5 mm. |
2n | = 14, 28. |
= 14. |
Oenothera havardii |
Oenothera triangulata |
|
Phenology | Flowering Apr–Oct. | Flowering Apr–Jul. |
Habitat | In depressions, seasonally wet flats, stream banks, margins of irrigated fields, sandy or clay soil, among tufted grasses like Sporobolus wrightii, primarily in Chihuahuan Desert. | Open, sandy sites. |
Elevation | 1300–2000 m. (4300–6600 ft.) | 200–600 m. (700–2000 ft.) |
Distribution |
AZ; TX; Mexico (Chihuahua, Durango, Sonora, Zacatecas) |
OK; TX |
Discussion | Oenothera havardii ranges from Brewster and Presidio counties, Texas, and Cochise County, Arizona, south to Durango and Zacatecas, Mexico. W. L. Wagner (1984) found that O. havardii is self-incompatible and vespertine. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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.) |
Source | FNA vol. 10. | FNA vol. 10. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | Hartmannia havardii, H. palmeri | Gaura triangulata, G. hexandra var. triangulata, G. tripetala var. triangulata |
Name authority | S. Watson: Proc. Amer. Acad. Arts 20: 366. (1885) — (as havardi) | (Buckley) W. L. Wagner & Hoch: Syst. Bot. Monogr. 83: 214. (2007) |
Web links |