Oenothera brachycarpa |
Oenothera psammophila |
|
---|---|---|
shortfruit evening-primrose |
St. Anthony dunes evening primrose |
|
Habit | Herbs acaulescent or sometimes caulescent, strigillose, also hirsute, hairs often with reddish purple pustulate base, glandular puberulent distally; from a woody taproot, sometimes lateral roots producing adventitious shoots. | Herbs perennial, caulescent, glabrous, also with resinous exudate, especially on younger leaves; from woody taproot. |
Stems | (when present) ascending, longer ones becoming decumbent, usually densely leafy, 0–20(–36) cm. |
decumbent, usually branched, 10–30 cm, becoming woody and buried in sand. |
Leaves | in a basal rosette, sometimes also cauline, (3.1–)5–21(–34) × (0.3–)1.5–3.5(–5.3) cm; petiole (0.8–)2.5–11(–15) cm; blade usually lanceolate to elliptic, rhombic-obovate, sometimes suborbicular or linear, usually irregularly pinnatifid, some sinuses extending nearly to midrib, usually with a large terminal lobe (0.1–)1.5–2(–2.4) cm, margins erose, apex acute to obtuse or rounded. |
(6–)8–9(–14.2) × (0.7–)1.5–2(–3.1) cm; petiole 3–9 cm; blade narrowly oblanceolate to oblanceolate, margins usually subentire or repand or remotely dentate, rarely serrate, apex acute. |
Flowers | usually 1–3, rarely more, opening per day near sunset, weakly scented; buds with unequal free tips 1–7 mm; floral tube (90–)120–210(–220) mm; sepals 38–55 mm; petals pale yellow to yellow, fading pale orange to pink, drying lavender to purple, usually broadly rhombic-obovate, sometimes obovate, (38–)45–58(–62) mm, distal margin usually erose; filaments (16–)20–32 mm, anthers (8–)13–21 mm; style (123–)155–240(–255) mm, stigma exserted beyond anthers at anthesis. |
1–3 per stem opening per day near sunset, with sweet scent; buds erect; floral tube 42–60 mm; sepals 22–28 mm; petals white, fading rose pink to rose, 23–40 mm; filaments 17–19 mm, anthers 13–16 mm; style 60–72(–88) mm, stigma exserted beyond anthers at anthesis. |
Capsules | leathery or corky, ovoid to narrowly ellipsoid, ± winged, wings 0–3(–5) mm wide, sometimes capsule with corky thickening between wings, then capsule only 4-angled, body (12–)18–40 × 6–10 mm, dehiscent 1/4 their length; pedicel 0–3 mm. |
somewhat curved and often somewhat twisted, lanceoloid-cylindrical, nearly cylindrical, (20–)30–47 × 7–8 mm, gradually tapering to apex, 6–8 mm, dehiscent nearly throughout their length, valve margins with a conspicuous, irregular, wavy ridge; pedicel 1–5 mm. |
Seeds | usually numerous, in 1 or 2 rows per locule, obovoid to subcuboid, 3–5 × 1.8–2.2 mm. |
numerous, in 2 distinct rows per locule, narrowly obovoid, 2.5–3 × 1.2–1.4 mm, embryo 7/8 of seed volume, surface finely reticulate; seed collar with a broad membrane sealing cavity, margin entire. |
2n | = 14. |
= 14. |
Oenothera brachycarpa |
Oenothera psammophila |
|
Phenology | Flowering Mar–Aug. | Flowering May–Jul. |
Habitat | Rocky sites, usually on limestone, shale, or gypsum, on igneous substrates from canyons and slopes in Chihuahuan Desert scrub, grasslands, oak-pine-juniper woodlands, open sites in ponderosa pine-Douglas fir forests. | On barren areas of drifting sand at interface between outcrops of lava and sand dunes. |
Elevation | 1000–2700 m. (3300–8900 ft.) | 1500–1700 m. (4900–5600 ft.) |
Distribution |
AZ; NM; TX; Mexico (Chihuahua, Coahuila, Durango, Sonora)
|
ID |
Discussion | Oenotherabrachycarpa occurs from southeastern Arizona in southern Navajo, southeastern Pima, Graham, Santa Cruz, and Cochise counties, east across southern New Mexico to Val Verde and Pecos counties in trans-Pecos Texas. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Oenothera psammophila is known only from the dune area north and west of St. Anthony, Fremont County. It is unique in Oenothera because of the exudate produced on the leaves to which sand particles adhere, forming a sand sheath, presumably for protection from the constantly blowing sand particles. It is self-incompatible (W. L. Wagner et al. 1985; Wagner 2005). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 10. | FNA vol. 10. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | Lavauxia brachycarpa, L. graminifolia, L. wrightii, Megapterium brachycarpum, M. brachycarpum var. wrightii, O. australis, O. brachycarpa var. wrightii, O. cespitosa subsp. australis, O. cespitosa var. australis, O. graminifolia, O. wrightii, Pachylophus australis | Pachylophus psammophilusa., O. cespitosa var. psammophila |
Name authority | A. Gray: Smithsonian Contr. Knowl. 3(5): 70. (1852) | (A. Nelson & J. F. Macbride) W. L. Wagner, Stockhouse & W. M. Klein: Monogr. Syst. Bot. Missouri Bot. Gard. 12: 84. (1985) |
Web links |