Oenothera arizonica |
Oenothera platanorum |
|
---|---|---|
California evening primrose |
Fort Huachuca evening primrose |
|
Habit | Herbs winter-annual, younger parts sparsely to densely strigillose and sparsely to densely hirsute, older stems glabrate; from a taproot. | Herbs perennial, caulescent, strigillose, often densely so; from slender taproot. |
Stems | ascending to erect, with decumbent branches, thickened at base, tapering toward apex, 10–35(–60) cm. |
1–several, ascending, 5–60 cm. |
Leaves | in a basal rosette and cauline, basal 5–10(–26) × 0.6–1.5(–3.5) cm, cauline 5–8(–15.5) × 1–2 cm; petiole 0–12 cm; blade lanceolate to oblanceolate, margins pinnatifid or sometimes coarsely serrate. |
in a basal rosette and cauline, basal 2–7 × 0.3–1.4 cm, blade narrowly elliptic to narrowly ovate, margins weakly serrulate to sinuate-pinnatifid; cauline 1.2–6 × 0.3–1 cm, blade narrowly elliptic to elliptic or ovate, proximal ones sinuate-pinnatifid, margins subentire or weakly serrulate. |
Inflorescences | erect. |
|
Flowers | 1–several opening per day near sunset; buds nodding, weakly quadrangular, without free tips; floral tube 26–31 mm; sepals 19–26 mm, conspicuously maroon-spotted, each spot at base of a long hair; petals white, fading pink to deep pink, broadly obovate or obcordate, 16–26(–36) mm; filaments 9–15 mm, anthers 7–9 mm; style 45–50 mm, stigma exserted beyond anthers at anthesis. |
1–3 opening per day near sunrise; buds with free tips 0–0.1 mm; floral tube 9–14 mm; sepals 7.5–13 mm; petals rose purple, fading darker, 8–15 mm; filaments 4–9 mm, anthers 2.5–4 mm, pollen 85–100% fertile; style 12–19 mm, stigma surrounded by anthers at anthesis. |
Capsules | spreading, woody in age, curved upward, or distal end recurved, cylindrical, obtusely 4-angled, especially toward base, tapering gradually from base to apex, 30–80 × 2.5–3.5 mm; sessile. |
clavate or narrowly obovoid, 9–14 × 3–4 mm, apex attenuate to a sterile beak, valve midrib prominent in distal part, proximal stipe 4–15 mm, gradually tapering to base; sessile. |
Seeds | numerous, in 1 row per locule, light brown to yellowish brown with dark purple splotches, obovoid, 1.6–2 mm. |
narrowly obovoid, 0.7–0.9 × 0.3–0.5 mm. |
2n | = 14. |
= 14. |
Oenothera arizonica |
Oenothera platanorum |
|
Phenology | Flowering (Oct–)Feb–May. | Flowering Mar–Aug. |
Habitat | Gravelly or sandy soil, along watercourses, disturbed sites. | Streambeds and near springs. |
Elevation | 200–1400 m. (700–4600 ft.) | 700–1900 m. (2300–6200 ft.) |
Distribution |
AZ; Mexico (Sonora) |
AZ; Mexico (Sonora) |
Discussion | Oenothera arizonica occurs in southern Arizona from Maricopa and Yuma counties to Cochise County, and from scattered localities in northern Sonora, Mexico, including Cerro Tepopa, Puerto Libertad, and Tastiota. The populations from southwestern Arizona (Yuma County) southward to Sonora often grow on low dunes. Populations from sand dunes in Yuma County, Cabeza Prieta National Wildlife Refuge, appear to be a large phenotype of Oenothera arizonica that differ from all other specimens in the size of vegetative parts and flowers, and comprise all of the atypical measurements given in the description. Oenothera arizonica typically grows on dunes in Sonora, but rarely so in Arizona. Populations growing on dunes should be studied further and compared to non-dune populations in the northern and eastern portion of the range. Oenothera arizonica is self-compatible (W. L. Wagner et al. 2007; K. E. Theiss et al. 2010). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Oenothera platanorum is known only from the southeastern counties of Cochise, Pinal, and Santa Cruz in Arizona. It was recently collected in Sonora, Mexico. The species is very similar to both O. texensis, from which it differs in its smaller flowers, and the widespread O. rosea, from which it differs in the somewhat larger flowers and in forming seven bivalents in meiosis and fully fertile pollen, whereas O. rosea is 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 | O. deltoides var. arizonica, O. avita subsp. arizonica, O. californica subsp. arizonica | |
Name authority | (Munz) W. L. Wagner: Novon 8: 308. (1998) | P. H. Raven & D. R. Parnell: Madroño 20: 246. (1970) |
Web links |