Oenothera curtiflora |
Oenothera sect. Gaura |
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lizard-tail, small-flower bee-blossom, small-flower gaura, velvet weed |
biennial bee-blossom |
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Habit | Herbs annual, strigillose, glandular puberulent, and long-villous; from heavy taproot, 2–4 cm diam. | Herbs annual, biennial, or perennial, caulescent; from a taproot, sometimes woody or producing rhizomes. | ||||||||||||||||||||||||||||
Stems | erect, unbranched or many-branched distally, (20–)30–200(–300) cm. |
usually erect or ascending, sometimes decumbent, branched or unbranched. |
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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. |
in a basal rosette and cauline (sometimes not present at flowering), (0.5–)2–8(–13) cm; blade margins sinuate-dentate to denticulate, serrate, lobed, or entire. |
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Inflorescences | relatively long, dense. |
solitary flowers in axils of distal leaves, forming a spike, erect or nodding. |
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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. |
opening near sunset or sunrise; buds erect, terete, without free tips; floral tube 1.5–20[–42] mm, usually lanate in distal 1/2 within; sepals splitting along one suture, remaining coherent and reflexed as a unit at anthesis, or separating in pairs or sometimes individually; petals white [rarely yellow], fading pink to red, purple, or off-white, spatulate to elliptic, rhombic, or, sometimes, oblanceolate, usually clawed; filaments with basal scale 0.3–0.5 mm, these nearly closing mouth of floral tube, or sometimes reduced or absent; stigma deeply divided into (3 or) 4 linear lobes. |
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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. |
woody and nutlike, ovoid, fusiform, lanceoloid, ellipsoid, obovoid, or pyramidal, (3- or)4-angled, sometimes weakly so, or (3- or)4-winged, apex acute to attenuate or, sometimes, rounded, indehiscent, septa fragile, not evident at maturity; sessile, sometimes disarticulating from plant at maturity. |
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Seeds | 3 or 4, reddish brown, 2–3 × 1–1.5 mm. |
reduced to 1–4(–8), usually ovoid, rarely oblanceoloid (O. glaucifolia), surface smooth. |
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2n | = 14. |
= 14, 28, 42, 56. |
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Oenothera curtiflora |
Oenothera sect. Gaura |
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Phenology | Flowering (Feb–)Apr–Oct. | |||||||||||||||||||||||||||||
Habitat | Rocky prairie slopes, woodlands, along streams, roadsides, disturbed areas. | |||||||||||||||||||||||||||||
Elevation | 10–2800 m. (0–9200 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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North America; Mexico; Central America (Guatemala) [Introduced in South America, Europe, Asia, s Africa, Australia] |
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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.) |
Species 25 (23 in the flora). Section Gaura consists of 25 species (26 taxa) that are subdivided into eight subsections [seven in the flora area; subsect. Gauridium (Spach) W. L. Wagner & Hoch is is found only in Mexico]. All species have indehiscent capsules, a feature otherwise found in Oenothera only in O. canescens (sect. Gauropsis). Oenothera havardii (sect. Paradoxus) and O. linifolia (sect. Peniophyllum) have tardily and only partially dehiscent capsules. Twenty-one species in four subsections (Campogaura, Gaura, Stipogaura, and Xenogaura) have zygomorphic flowers; the other four subsections (Gauridium, Schizocarya, Stenosiphon, and Xerogaura), each with a single species, have actinomorphic, or nearly actinomorphic, flowers. Since Linnaeus described Gaura, it has been maintained as distinct at the generic level and, at various times, even at the tribal level. Its distinct status rested on several characteristic features including a scale at the base of the filaments; a peltate indusium at the base of the stigma; indehiscent, nutlike capsules; and seeds reduced to 1–4(–8) (P. H. Raven and D. P. Gregory 1972[1973]; W. L. Wagner et al. 2007). The most recent molecular studies (G. D. Hoggard et al. 2004; R. A. Levin et al. 2004) place Gaura strongly within the Oenothera clade and equally strongly in a clade with other sections possessing winged/angled capsules that are sometimes indehiscent or nearly so. Hoggard et al. found strong support for the inclusion of the monotypic Stenosiphon within Gaura; Levin et al. concurred, finding strong support for the monophyly of the Gaura lineage, but placed it unequivocally within Oenothera. Reconsidering the distinctive features of Gaura, Wagner et al. found that the indusium characterizes the whole genus Oenothera, and the indehiscent fruits seem to characterize a larger clade in the genus. The reduction in seed number appears to be a strong synapomorphy for the reconstituted Oenothera sect. Gaura. Wagner et al. recognized eight subsections within sect. Gaura that also includes Stenosiphon. The subsections are arranged according to the synthesis of morphological characters, crossing analyses, and molecular data (Raven and Gregory; Wagner et al.). Oenothera anomala Curtis and O. hexandra (Ortega) W. L. Wagner & Hoch are Mexican species that occur well south of the flora area. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Key |
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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 | ||||||||||||||||||||||||||||
Sibling taxa | ||||||||||||||||||||||||||||||
Subordinate taxa | ||||||||||||||||||||||||||||||
Synonyms | Gaura parviflora, G. australis, G. hirsuta, G. micrantha, G. parviflora var. lachnocarpa, Schizocarya micrantha | Gaura | ||||||||||||||||||||||||||||
Name authority | W. L. Wagner & Hoch: Syst. Bot. Monogr. 83: 211. (2007) | (Linnaeus) W. L. Wagner & Hoch: Syst. Bot. Monogr. 83: 165. (2007) | ||||||||||||||||||||||||||||
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