Oenothera canescens |
Oenothera arizonica |
|
---|---|---|
beakpod evening primrose, spotted evening-primrose |
California evening primrose |
|
Habit | Herbs low, forming clumps 10–50 cm diam., densely strigillose throughout; from a taproot, lateral roots producing adventitious shoots. | Herbs winter-annual, younger parts sparsely to densely strigillose and sparsely to densely hirsute, older stems glabrate; from a taproot. |
Stems | many-branched from base, leafy, (10–)15–25(–38) cm. |
ascending to erect, with decumbent branches, thickened at base, tapering toward apex, 10–35(–60) cm. |
Leaves | cauline, (0.3–)0.6–1.5(–2.5) × (0.05–)0.15–0.4(–0.6) cm, fascicles of small leaves 0.2–0.6 cm often present in non-flowering axils; petiole 0–0.1 cm; blade lanceolate to linear, base cuneate, apex acute. |
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. |
Flowers | several opening per day near sunset; buds usually without free tips, rarely free tips 0.2–0.3 mm; sepals (7–)8–12 mm; petals pink, rarely white, streaked or flecked with red, fading bright purple, (8–)10–17 mm; filaments 6–8 mm, anthers often with red longitudinal stripe, 3–6 mm; style (16–)22–27 mm, stigma exserted beyond anthers at anthesis. |
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. |
Capsules | woody, ovoid, narrowly winged, wings 0.8–1.5 mm wide, (7–)9–12(–14) × 2–4 mm (excluding wings), abruptly constricted to a conspicuous, sterile beak, (2–)3–4.5 mm, indehiscent; sessile. |
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. |
Seeds | asymmetrically cuneiform or oblanceoloid, 1.2–1.5 × 0.4–0.5 mm. |
numerous, in 1 row per locule, light brown to yellowish brown with dark purple splotches, obovoid, 1.6–2 mm. |
2n | = 14. |
= 14. |
Oenothera canescens |
Oenothera arizonica |
|
Phenology | Flowering May–Aug. | Flowering (Oct–)Feb–May. |
Habitat | Prairie depressions, playas, margins of ditches, temporary wet areas. | Gravelly or sandy soil, along watercourses, disturbed sites. |
Elevation | (400–)700–1800 m. ((1300–)2300–5900 ft.) | 200–1400 m. (700–4600 ft.) |
Distribution |
CO; KS; NE; NM; OK; TX; WY
|
AZ; Mexico (Sonora) |
Discussion | Oenothera canescens is restricted to prairie depressions, playas, ditch margins, and other places of temporary water in the High Plains of the western United States from Goshen County, Wyoming, southeast to Hayes County, Nebraska, south through eastern Colorado, the eastern tier of counties in New Mexico, western Kansas, and to Garza and Dawson counties in the Texas Panhandle; also disjunct populations from Chautauqua, Sedgwick, and Stafford counties, Kansas. The illegitimate names Gaurella guttulata (Geyer ex Hooker) Small, G. canescens (Torrey & Frémont) Cockerell, and Gauropsis guttulata (Geyer ex Hooker) Cockerell pertain here. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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.) |
Source | FNA vol. 10. | FNA vol. 10. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | Gaurella canescens, Megapterium canescens, O. guttulata | O. deltoides var. arizonica, O. avita subsp. arizonica, O. californica subsp. arizonica |
Name authority | Torrey & Frémont in J. C. Fremont: Rep. Exped. Rocky Mts., 315. (1845) | (Munz) W. L. Wagner: Novon 8: 308. (1998) |
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