Oenothera curtiflora |
Oenothera psammophila |
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lizard-tail, small-flower bee-blossom, small-flower gaura, velvet weed |
St. Anthony dunes evening primrose |
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Habit | Herbs annual, strigillose, glandular puberulent, and long-villous; from heavy taproot, 2–4 cm diam. | Herbs perennial, caulescent, glabrous, also with resinous exudate, especially on younger leaves; from woody taproot. |
Stems | erect, unbranched or many-branched distally, (20–)30–200(–300) cm. |
decumbent, usually branched, 10–30 cm, becoming woody and buried in sand. |
Leaves | in a basal rosette and cauline, basal 4–15 × 1.5–3 cm, petiole 0–1.8 cm, blade broadly oblanceolate, margins sinuate-dentate to dentate; cauline 2–13 × 0.5–5 cm, petiole 0–2 cm, blade narrowly elliptic to narrowly ovate, margins sinuate-dentate to dentate. |
(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. |
Inflorescences | relatively long, dense. |
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Flowers | 4-merous, nearly actinomorphic, opening near sunset; floral tube 1.5–5 mm; sepals 2–3.5 mm; petals white, fading pale to dark pink, slightly unequal, oblong-obovate to elliptic-oblanceolate, 1.5–3 mm, abruptly clawed; filaments 1.5–3 mm, anthers 0.5–1 mm, pollen 85–100% fertile; style 3–9 mm, stigma surrounded by 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 | fusiform, terete, weakly angled in distal 1/3, angles becoming broad and rounded in proximal part, 5–11 × 1.5–3 mm, tapering abruptly toward base; sessile. |
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 | 3 or 4, reddish brown, 2–3 × 1–1.5 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 curtiflora |
Oenothera psammophila |
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Phenology | Flowering (Feb–)Apr–Oct. | Flowering May–Jul. |
Habitat | Rocky prairie slopes, woodlands, along streams, roadsides, disturbed areas. | On barren areas of drifting sand at interface between outcrops of lava and sand dunes. |
Elevation | 10–2800 m. (0–9200 ft.) | 1500–1700 m. (4900–5600 ft.) |
Distribution |
AL; AR; AZ; CA; CO; FL; GA; IA; ID; IL; IN; KS; KY; LA; MA; MD; MN; MO; MT; NE; NM; NV; OK; OR; SC; SD; TN; TX; UT; VA; WA; WY; Mexico (Baja California, Chihuahua, Coahuila, Durango, Nuevo León, Sinaloa, Zacatecas) [Introduced in South America (Argentina), Asia (China, Japan), Australia]
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ID |
Discussion | Oenothera curtiflora is self-compatible and autogamous (P. H. Raven and D. P. Gregory 1972[1973]). Sometimes it is apparently a biennial. The species is native to grassland regions and open areas across much of interior North America. The full extent of its indigenous range is not clear and collections from the eastern half of the United States (Alabama, Florida, Georgia, Indiana, Massachusetts, and Tennessee) and California may be more recent introductions. Gaura mollis Nuttall ex Torrey 1827 is an isonym of G. mollis E. James 1822, a suppressed name. (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 | Onagraceae > subfam. Onagroideae > tribe Onagreae > Oenothera > sect. Gaura > subsect. Schizocarya | Onagraceae > subfam. Onagroideae > tribe Onagreae > Oenothera > sect. Pachylophus |
Sibling taxa | ||
Synonyms | Gaura parviflora, G. australis, G. hirsuta, G. micrantha, G. parviflora var. lachnocarpa, Schizocarya micrantha | Pachylophus psammophilusa., O. cespitosa var. psammophila |
Name authority | W. L. Wagner & Hoch: Syst. Bot. Monogr. 83: 211. (2007) | (A. Nelson & J. F. Macbride) W. L. Wagner, Stockhouse & W. M. Klein: Monogr. Syst. Bot. Missouri Bot. Gard. 12: 84. (1985) |
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