The green links below add additional plants to the comparison table. Blue links lead to other Web sites.
enable glossary links

false gaura

stemless evening-primrose

Habit Herbs probably biennial, glabrous, becoming sparsely to densely glandular puberulent and short-villous distally, glaucous at least in proximal parts; from stout roots. Herbs winter-annual, sometimes biennial, acaulescent or very short-caulescent, sparsely to moderately strigillose and glandular puberulent, sometimes one hair type predominant, rarely glabrate, sometimes also very sparsely hirsute, especially on leaf veins; from a slender or, sometimes, stout taproot.
Stems

erect, branched or unbranched, 30–300 cm.

(when present) ascending, 1–several, densely leafy, 0–20 cm.

Leaves

in a basal rosette and cauline, basal 3–7 × 0.5–2 cm, sessile, blade oblong to oblong-lanceolate, base usually ± auriculate, margins entire;

cauline 3–8(–10) × 0.4–1.8 cm, blade lanceolate to oblong-lanceolate, gradually smaller, becoming linear-subulate distally.

in a basal rosette, sometimes also cauline, (2.5–)6–25(–32) × (0.6–)1.5–4(–5) cm, thin;

petiole (0.5–)1–8 cm;

blade oblanceolate to elliptic, margins irregularly pinnatifid, sometimes subentire, apex acute to obtuse or rounded.

Inflorescences

long, wandlike, unbranched or branched.

Flowers

4-merous, nearly actinomorphic, opening near sunrise;

floral tube 6–17 mm;

sepals 4–6 mm;

petals white, fading off-white or tinged pink, slightly unequal, rhombic, 4–6 mm, abruptly clawed;

filaments 5–8 mm, anthers 1.5–2 mm, pollen 85–100% fertile;

style 6–10, stigma exserted beyond anthers at anthesis.

1–4 opening per day near sunset, without noticeable scent;

buds with subequal free tips 2–7 mm;

floral tube (20–)28–95(–138) mm;

sepals (6–)10–30(–35) mm;

petals pale yellow, fading pale orange, drying lavender, (10–)12–30(–38) mm;

filaments (5–)8–15(–18) mm, anthers (3.5–)4–11 mm;

style (3.4–)4.2–11.5(–16.3) mm, stigma usually surrounded by anthers, sometimes (especially in some Texas populations) exserted beyond anthers.

Capsules

ovoid, 4-angled, somewhat flattened, 3–4 × 1.5–2.3 mm, valves with raised midrib and conspicuous lateral veins;

sessile.

woody in age, rhombic-obovoid, winged, wings broadly triangular, 5–10 mm wide, often terminating in a hooked tooth, (10–)15–25(–28) × 4–8 mm (excluding wings), valve surface reticulate, dehiscent 1/8–1/3 their length.

Seeds

1, pale yellow, oblanceoloid, 2.4–2.6 × 1–1.5 mm.

asymmetrically cuneiform, (2.1–)2.5–3(–3.3) mm.

2n

= 14.

= 14.

Oenothera glaucifolia

Oenothera triloba

Phenology Flowering May–Oct(–Nov). Flowering (Feb–)Mar–May(–Jul).
Habitat Rocky prairie slopes and outcrops or bluffs, along streams, roadsides, usuallyon limestone. Scattered to common in clay, sandy or rocky soil, playas, floodplains, creek beds, slopes and flats, moist sites, disturbed sites, roadsides, old fields, in Larrea deserts, prairies, glades.
Elevation 200–1300 m. (700–4300 ft.) 300–1900 m. (1000–6200 ft.)
Distribution
from FNA
AR; CO; KS; MO; NE; NM; OK; TX; WY
[WildflowerSearch map]
[BONAP county map]
from FNA
AL; AR; CO; DC; IL; IN; KS; KY; MD; MO; NM; OH; OK; PA; TN; TX; VA; Mexico (Baja California, Chihuahua, Nuevo León)
[WildflowerSearch map]
[BONAP county map]
Discussion

Oenothera glaucifolia is self-incompatible, the flowers diurnal, pollinated primarily by wasps (R. Clinebell, unpubl.), as well as bees, flies, butterflies, and occasionally beetles (summarized by W. L. Wagner et al. 2007). It was collected once in 1988 in Indiana at Miller Woods Visitor Center (Lake County), Dritz 596 (MOR); it seems likely that it was introduced, and has not been collected there since.

Stenosiphon virgatus Spach is a superfluous name and pertains here.

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

Oenotheratriloba is primarily a species of the high plains from eastern Socorro County, New Mexico, east through all but eastern Texas, Oklahoma, to southern Kansas, east of Meade and Pawnee counties and south of Douglas and Saline counties. It becomes more sporadic eastward into Missouri south of the Missouri River, northwestern and north-central Arkansas, central and eastern Tennessee, northern Alabama, and Logan and Warren counties, Kentucky; also known from disjunct sites in northern Mexico from Nuevo León, Chihuahua, and Baja California, Mexico; and, introduced in Illinois, Indiana, Ohio, Kentucky (Campbell and Fayette counties), Pennsylvania, Virginia, Maryland, and the District of Columbia. Areas where it was introduced are represented by old collections; no current information indicates their continued presence in any of these areas. It was recently collected in Baca County, Colorado.

Capsules of dead plants sometimes form pineconelike clusters of ten to 100 or more capsules.

The illegitimate names Lavauxia nuttalliana Spach and L. triloba (Nuttall) Spach var. watsonii Britton pertain here.

(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. Stenosiphon Onagraceae > subfam. Onagroideae > tribe Onagreae > Oenothera > sect. Lavauxia > subsect. Lavauxia
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. 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
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. sinuosa, O. spachiana, O. speciosa, O. stricta, O. suffrutescens, O. suffulta, O. tetraptera, O. texensis, O. toumeyi, O. triangulata, O. tubicula, O. villosa, O. wolfii, O. xylocarpa
Synonyms Gaura linifolia, Stenosiphon linifolius Lavauxiahamata wooton, L. triloba, L. watsonii, O. hamata, O. rhizocarpa, O. roemeriana, O. triloba var. parviflora, O. triloba
Name authority W. L. Wagner & Hoch: Syst. Bot. Monogr. 83: 212. (2007) Nuttall: J. Acad. Nat. Sci. Philadelphia 2: 118. (1821)
Web links