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royal evening primrose

Habit Herbs perennial, sometimes suffrutescent, usually strigillose, sometimes glabrous; from a stout taproot. Herbs annual, moderately to sparsely strigillose and villous, sometimes glandular puberulent distally.
Stems

many, ascending to erect, branched from base, 15–30(–40) cm.

erect to ascending, usually unbranched, 10–40 cm.

Leaves

2.5–3.5 × 0.1–0.2 cm, rarely fascicles of small leaves present in non-flowering axils;

petiole 0–0.1 cm;

blade linear to narrowly linear-lanceolate, folded lengthwise, base long-attenuate, margins subentire or serrulate, apex acute.

in a basal rosette and cauline, basal 5–12 ×1.3–3.5 cm, cauline 2–8.5 ×1–3 cm;

blade green, narrowly oblanceolate to narrowly elliptic or narrowly lanceolate, margins usually dentate to pinnatifid, sometimes subentire;

bracts spreading, flat.

Flowers

opening near sunrise;

buds with free tips 0–0.5 mm;

floral tube 7 mm;

sepals 4–6 mm, midribs keeled;

petals yellow, fading yellow to orange, 15–20 mm; antisepalous filaments 5 mm, antipetalous filaments 2 mm, anthers 3–4 mm, pollen 90–100% fertile;

style 10 mm, stigma discoid to quadrangular, exserted beyond anthers at anthesis.

usually 1 opening per day near sunset;

buds erect, with free tips erect, 0.5–2 mm;

floral tube 25–40 mm;

sepals 10–22 mm;

petals yellow, fading orange or reddish tinged, broadly obovate or shallowly obcordate, 13–25 mm;

filaments 10–17 mm, anthers 4–5 mm, pollen 85–100% fertile;

style 35–50 mm, stigma slightly exserted beyond anthers at anthesis.

Capsules

18–20 × 2 mm, hard, dehiscent 1/2 their length, often tardily dehiscent throughout their length.

cylindrical, sometimes slightly enlarged toward apex, 20–45 × 2–2.5 mm.

Seeds

oblanceoloid, 1–1.8 mm, sharply angled, apex truncate.

ellipsoid, 0.8–1.4 × 0.3–0.6 mm.

2n

= 14.

= 14.

Oenothera gayleana

Oenothera falfurriae

Phenology Flowering May–Sep. Flowering Apr–Aug.
Habitat Gypsum outcrops. Open, sandy sites.
Elevation 500–1400 m. (1600–4600 ft.) 0–300 m. (0–1000 ft.)
Distribution
from FNA
NM; TX
[BONAP county map]
from FNA
TX
[BONAP county map]
Discussion

Oenothera gayleana is a recently discovered gypsum endemic known only from scattered outcrops from De Baca and Eddy counties in New Mexico, and Culberson County in Texas. When published, the delimitation of O. gayleana included populations in Collinsworth and Dickens counties in the Texas panhandle, and adjacent Harmon County in Oklahoma. Subsequent study (B. Cooper et al., unpubl.) has determined they are actually O. serrulata.

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

Oenothera falfurriae is known only from southeastern Texas (Aransas, Brazos, Brooks, Cameron, Frio, Harris, Hidalgo, Jim Hogg, Jim Wells, Kenedy, Kleberg, Maverick, Nueces, Refugio, Starr, Val Verde, Victoria, Webb, Willacy, Wilson, and Zapata counties). It is self-compatible and autogamous, but not a PTH species.

(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. Calylophus > subsect. Calylophus Onagraceae > subfam. Onagroideae > tribe Onagreae > Oenothera > sect. Oenothera > subsect. Raimannia
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. 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
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. 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
Name authority B. L. Turner & M. J. Moore: Phytologia 96: 200, figs. 1, 2. (2014) W. Dietrich & W. L. Wagner: Ann. Missouri Bot. Gard. 74: 149. (1987)
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