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wavy-leaf gaura, wavyleaf beeblossom

Engelmann's evening-primrose

Habit Herbs perennial, usually glabrous, sometimes strigillose and villous, hairs erect; from a woody taproot but spreading by rhizomes (forming extensive colonies). Herbs winter-annual, conspicuously villous throughout, also strigillose on leaves and distal parts; from a taproot.
Stems

erect, branched below and just above ground, branched also proximal to inflorescences, 40–120(–250) cm.

erect, unbranched or with few, spreading branches, 30–50(–80) cm.

Leaves

in a basal rosette and cauline, (1–)3–11 × (0.1–)0.5–2 cm, blade linear to narrowly oblanceolate, margins usually sparsely sinuate-dentate, rarely subentire, often undulate.

in a basal rosette and cauline, rosette weakly developed or absent, at least during flowering, (1–)2–6(–8) × 1–2(–3) cm;

sessile;

blade lanceolate to oblong lanceolate, proximal ones sometimes oblanceolate, margins coarsely repand-dentate or -pinnatifid.

Inflorescences

stout.

Flowers

4-merous, zygomorphic, opening near sunset;

floral tube 2.5–5 mm;

sepals 7–14 mm;

petals white, fading pink to red, slightly unequal, elliptic, 7–15 mm;

stamens presented in lower 1/2 of flower, filaments 5–11 mm, lanate at very base, anthers 3–5 mm, pollen 90–100% fertile;

style 12–19 mm, stigma exserted beyond anthers at anthesis.

1–several opening per day near sunset;

buds nodding, weakly quadrangular, without free tips;

floral tube 20–30 mm;

sepals 13–21 mm, not spotted or with scattered small, maroon spots;

petals white, fading pink, broadly obovate or obcordate, 15–30 mm;

filaments 14–16 mm, anthers 6–8 mm;

style 40–50 mm, stigma exserted beyond anthers at anthesis.

Capsules

narrowly ovoid, narrowly 4-winged or 4-angled, 8–15 × 1.5–3.5 mm, abruptly constricted to a long, sterile stipe 2–8 mm.

widely spreading, woody in age, straight or slightly curved, cylindrical, obtusely 4-angled, especially toward base, tapering gradually from base to apex, 30–60 × 2–3 mm;

sessile.

Seeds

(1 or)2–4, light to reddish brown, 2–3 × 1–1.5 mm.

numerous, in 1 row per locule, brown, narrowly obovoid, 1–1.5 mm.

2n

= 28.

= 14.

Oenothera sinuosa

Oenothera engelmannii

Phenology Flowering Apr–Aug. Flowering Apr–Aug(–Sep).
Habitat Flats and washes in light sandy loam. Sandy prairies, dunes, disturbed areas, roadsides.
Elevation 0–300(–1300) m. (0–1000(–4300) ft.) 500–1300 m. (1600–4300 ft.)
Distribution
from FNA
AL; AR; CA; FL; GA; MO; NY; OK; TX [Introduced in Europe (Italy), s Africa]
[WildflowerSearch map]
[BONAP county map]
from FNA
CO; KS; NM; OK; TX
[WildflowerSearch map]
[BONAP county map]
Discussion

P. H. Raven and D. P. Gregory (1972[1973]) determined Oenothera sinuosa to be self-incompatible.

Oenothera sinuosa is endemic to Oklahoma and Texas and is escaped or naturalized in Alabama, Arkansas, California (where found to 1300 m), Florida, Georgia, Missouri, and New York.

Oenothera sinuosa is potentially a noxious weed due to the aggressive rhizomatous habit, but is somewhat limited by its self-incompatibility. Molecular data (G. D. Hoggard et al. 2004) are consistent with the hypothesis that the allotetraploid (2n = 28) O. sinuosa arose by interspecific hybridization of two species within subsect. Stipogaura as suggested by P. H. Raven and D. P. Gregory (1972[1973]). The molecular data indicate that the pistillate parent came from O. calcicola or a close relative, while the staminate parent originated from the lineage that gave rise to O. cinerea and O. filipes.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Oenothera engelmannii is self-incompatible (W. L. Wagner et al. 2007; K. E. Theiss et al. 2010). It has a relatively narrow distribution in sandy areas of eastern New Mexico and western Texas, extending to southeastern Colorado, western Oklahoma, and southwestern Kansas. The flower size seems to vary, with larger flowers in eastern New Mexico and considerably smaller flowers in the eastern part of its range.

(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. Stipogaura Onagraceae > subfam. Onagroideae > tribe Onagreae > Oenothera > sect. Anogra
Sibling taxa
O. acutissima, O. albicaulis, O. argillicola, O. arida, O. arizonica, O. biennis, O. boquillensis, O. brachycarpa, O. calcicola, O. californica, O. canescens, O. capillifolia, O. cavernae, O. cespitosa, O. cinerea, O. clelandii, O. coloradensis, O. cordata, O. coronopifolia, O. coryi, O. curtiflora, O. curtissii, O. deltoides, O. demareei, O. dodgeniana, O. drummondii, O. elata, O. engelmannii, O. falfurriae, O. filiformis, O. filipes, O. flava, O. fruticosa, O. gaura, O. gayleana, O. glaucifolia, O. glazioviana, O. grandiflora, O. grandis, O. harringtonii, O. hartwegii, O. havardii, O. heterophylla, O. hispida, O. howardii, O. humifusa, O. jamesii, O. kunthiana, O. laciniata, O. lavandulifolia, O. lindheimeri, O. linifolia, O. longissima, O. macrocarpa, O. mckelveyae, O. mexicana, O. nealleyi, O. neomexicana, O. nutans, O. nuttallii, O. oakesiana, O. organensis, O. pallida, O. parviflora, O. patriciae, O. perennis, O. pilosella, O. platanorum, O. podocarpa, O. primiveris, O. psammophila, O. pubescens, O. rhombipetala, O. riparia, O. rosea, O. serrulata, O. sessilis, O. simulans, O. spachiana, O. speciosa, O. stricta, O. suffrutescens, O. suffulta, O. tetraptera, O. texensis, O. toumeyi, O. triangulata, O. triloba, O. tubicula, O. villosa, O. wolfii, O. xylocarpa
O. acutissima, O. albicaulis, O. argillicola, O. arida, O. arizonica, O. biennis, O. boquillensis, O. brachycarpa, O. calcicola, O. californica, O. canescens, O. capillifolia, O. cavernae, O. cespitosa, O. cinerea, O. clelandii, O. coloradensis, O. cordata, O. coronopifolia, O. coryi, O. curtiflora, O. curtissii, O. deltoides, O. demareei, O. dodgeniana, O. drummondii, O. elata, O. falfurriae, O. filiformis, O. filipes, O. flava, O. fruticosa, O. gaura, O. gayleana, O. glaucifolia, O. glazioviana, O. grandiflora, O. grandis, O. harringtonii, O. hartwegii, O. havardii, O. heterophylla, O. hispida, O. howardii, O. humifusa, O. jamesii, O. kunthiana, O. laciniata, O. lavandulifolia, O. lindheimeri, O. linifolia, O. longissima, O. macrocarpa, O. mckelveyae, O. mexicana, O. nealleyi, O. neomexicana, O. nutans, O. nuttallii, O. oakesiana, O. organensis, O. pallida, O. parviflora, O. patriciae, O. perennis, O. pilosella, O. platanorum, O. podocarpa, O. primiveris, O. psammophila, O. pubescens, O. rhombipetala, O. riparia, O. rosea, O. serrulata, O. sessilis, O. simulans, O. sinuosa, O. spachiana, O. speciosa, O. stricta, O. suffrutescens, O. suffulta, O. tetraptera, O. texensis, O. toumeyi, O. triangulata, O. triloba, O. tubicula, O. villosa, O. wolfii, O. xylocarpa
Synonyms Gaura sinuata Anogra pallida var. engelmannii, A. engelmannii
Name authority W. L. Wagner & Hoch: Syst. Bot. Monogr. 83: 214. (2007) (Small) Munz: Amer. J. Bot. 18: 316. (1931) — (as engelmanni)
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