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false gaura

fragrant evening-primrose, tuft 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 perennial, acaulescent or caulescent, usually hirsute or villous, usually also glandular puberulent, or exclusively strigillose, rarely glabrous; from stout taproot, sometimes lateral roots producing adventitious shoots.
Stems

erect, branched or unbranched, 30–300 cm.

(when present), usually ascending or decumbent, unbranched or branched from near base, 0–40 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.

1.7–26(–36) × (0.3–)0.5–4.5(–6.5) cm;

petiole (0.2–)1.7–11(–14) cm;

blade usually oblanceolate to rhombic or spatulate, rarely elliptic, obovate, lanceolate, or linear-oblanceolate, margins irregularly sinuate-dentate, serrate, pinnatifid, lobed, or subentire, apex usually acute to rounded, rarely acuminate.

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(–6) per stem opening per day near sunset, with moderate to strong sweet scent with a rubbery background scent;

buds usually erect, rarely recurved (during early development);

floral tube (20–)40–140(–165) mm;

sepals (15–)18–45(–54) mm;

petals white, fading rose or rose pink to dark or deep rose purple, or pink to pale or light rose, or lavender, obovate or obcordate, (16–)20–50(–60) mm;

filaments (6–)10–30(–35) mm, anthers (6–)9–17(–20) mm;

style (45–)60–180(–185) mm, stigma exserted beyond anthers at anthesis.

Capsules

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

sessile.

straight, curved, falcate, or sigmoid, usually cylindrical to lanceoloid or ellipsoid, sometimes ovoid, usually obtusely 4-angled, (10–)13–50(–68) × 4–9 mm, tapering to a sterile beak 6–8 mm, valve margins with rows of distinct tubercles to sinuate or nearly smooth ridges, dehiscent 1/3–7/8 their length;

pedicel (0–)1–40(–55) mm.

Seeds

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

numerous in 1 or 2 rows per locule, usually obovoid, oblong, or triangular, rarely suborbicular, 2.1–3.9 × 1–2.6 mm, embryo 1/5–2/3 of seed volume, surface papillose, reticulate or rarely irregularly roughened;

seed collar sealed by a thin membrane, this flat or depressed into raphial cavity, when depressed often splitting, becoming separated from seed collar.

2n

= 14.

= 14, 28.

Oenothera glaucifolia

Oenothera cespitosa

Phenology Flowering May–Oct(–Nov).
Habitat Rocky prairie slopes and outcrops or bluffs, along streams, roadsides, usuallyon limestone.
Elevation 200–1300 m. (700–4300 ft.)
Distribution
from FNA
AR; CO; KS; MO; NE; NM; OK; TX; WY
[WildflowerSearch map]
[BONAP county map]
from USDA
w North America; nw Mexico
[WildflowerSearch 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.)

Subspecies 5 (5 in the flora).

Oenothera cespitosa occurs in a wide array of habitats, from grassland, desert scrub, pinyon-juniper woodland, or Arizona chaparral to montane conifer forests, rarely at timberline, at elevations from (450–)800–3370 m. Oenothera cespitosa is self-incompatible (W. L. Wagner et al. 1985; Wagner 2005).

Pachylophus nuttallii Spach is an illegitimate name that pertains here.

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

Key
1. Plants glabrous.
→ 2
2. Floral tubes (28–)35–60(–85) mm; petals fading rose pink to dark rose purple; capsules falcate or sigmoid, valve margins tuberculate.
subsp. cespitosa
2. Floral tubes (45–)75–110(–153) mm; petals fading pink or rarely pale rose; capsules somewhat curved, valve margins with smooth to irregular, undulate ridges.
subsp. macroglottis
1. Plants hirsute, villous, glandular puberulent, or strigillose.
→ 3
3. Plants strigillose, rarely glandular puberulent; petals fading rose pink to dark rose purple.
subsp. cespitosa
3. Plants hirsute or villous, usually also glandular puberulent, rarely only glandular puberulent; petals fading pink to light or pale rose or lavender-rose, sometimes deep rose purple.
→ 4
4. Stems unbranched to many-branched, sometimes producing dense clumps 5–50 cm diam.; petals fading rose; seed collar sinuate distally.
subsp. crinita
4. Stems unbranched to several-branched, not forming clumps; petals fading rose purple or pink to pale rose or lavender; seed collar various.
→ 5
5. Petals fading rose or sometimes deep rose purple; capsules ellipsoid to lanceoloid-ellipsoid, falcate or sigmoid; pedicels 0.5–1 mm; seed collar membrane depressed and often splitting at maturity, margin conspicuously sinuate throughout.
subsp. crinita
5. Petals fading pink to pale rose or lavender; capsules lanceoloid to cylindrical, straight or somewhat curved; pedicels usually (0–)1–40(–55) mm; seed collar membrane neither depressed nor splitting at maturity, margin not sinuate, sometimes somewhat so distally.
→ 6
6. Capsules oblong-lanceoloid; buds often recurved when young; floral tube (35–)40–70(–80) mm; plants shaggy-villous, sometimes densely so.
subsp. navajoensis
6. Capsules cylindrical to lanceoloid-cylindrical; buds erect; floral tube (41–)75–140-(–165) mm; plants hirsute.
→ 7
7. Capsules somewhat curved, valve margins with nearly smooth to irregular, undulate ridges; leaf blades oblanceolate to spatulate, margins dentate.
subsp. macroglottis
7. Capsules straight, valve margins with minute to conspicuous tubercles, these sometimes coalesced into a sinuate ridge; leaf blades usually oblanceolate to narrowly elliptic, rarely lanceolate, margins usually pinnately lobed to dentate, rarely serrate.
subsp. marginata
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. Pachylophus
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. 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. triloba, O. tubicula, O. villosa, O. wolfii, O. xylocarpa
Subordinate taxa
O. cespitosa subsp. cespitosa, O. cespitosa subsp. crinita, O. cespitosa subsp. macroglottis, O. cespitosa subsp. marginata, O. cespitosa subsp. navajoensis
Synonyms Gaura linifolia, Stenosiphon linifolius Pachylophus cespitosus
Name authority W. L. Wagner & Hoch: Syst. Bot. Monogr. 83: 212. (2007) Nuttall: Cat. Pl. Upper Louisiana, no. 53. (1813)
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