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royal evening primrose

variableleaf evening primrose

Habit Herbs annual, moderately to sparsely strigillose and villous, sometimes glandular puberulent distally. Herbs annual or short-lived perennial, sparsely to densely strigillose, inflorescence sometimes also sparsely glandular puberulent, villous, or sparsely hirsute with spreading, pustulate-based hairs, or sometimes glabrate.
Stems

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

unbranched or branched mainly in distal part, 25–70 cm.

Leaves

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.

in a basal rosette and cauline, basal 7–15 × 1–2.5 cm, cauline 3–13 ×0.4–2.3 cm;

blade narrowly oblanceolate to oblanceolate, gradually narrowly lanceolate to lanceolate or elliptic distally, margins deeply lobed to remotely dentate or subentire;

bracts longer than capsule they subtend, 1–3 cm.

Inflorescences

dense, often with several lateral branches, mature buds usually overtopping spike apex.

Flowers

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.

2–several per spike opening per day near sunset;

buds erect, with free tips erect or spreading, 1–6 mm;

floral tube nearly straight, 25–47 mm;

sepals 15–30 mm;

petals yellow, broadly elliptic to nearly rhombic, 18–35 mm;

filaments 15–30 mm, anthers 3–8 mm, pollen 85–100% fertile;

style 45–75 mm, stigma usually exserted beyond anthers at anthesis.

Capsules

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

lanceoloid, 13–25 × 2.5–4 mm.

Seeds

ellipsoid, 0.8–1.4 × 0.3–0.6 mm.

brown, often flecked with darker spots, ellipsoid to broadly ellipsoid, 1.1–1.8 × 0.4–0.8 mm.

2n

= 14.

Oenothera falfurriae

Oenothera heterophylla

Phenology Flowering Apr–Aug.
Habitat Open, sandy sites.
Elevation 0–300 m. (0–1000 ft.)
Distribution
from FNA
TX
[BONAP county map]
from USDA
s United States
[BONAP county map]
Discussion

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.)

Subspecies 2 (2 in the flora).

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

Key
1. Herbs densely to sparsely strigillose, also at least parts of inflorescence sparsely hirsute with spreading, pustulate-based hairs, and often glandular puberulent and villous; flower buds with free tips spreading, 2–6 mm.
subsp. heterophylla
1. Herbs densely to sparsely strigillose, also at least part of inflorescence glabrate or glandular puberulent; flower buds with free tips erect, 1–3 mm.
subsp. orientalis
Source FNA vol. 10. FNA vol. 10.
Parent taxa Onagraceae > subfam. Onagroideae > tribe Onagreae > Oenothera > sect. Oenothera > subsect. Raimannia Onagraceae > subfam. Onagroideae > tribe Onagreae > Oenothera > sect. Oenothera > subsect. Candela
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. 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
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. 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. heterophylla subsp. heterophylla, O. heterophylla subsp. orientalis
Synonyms Raimannia heterophylla
Name authority W. Dietrich & W. L. Wagner: Ann. Missouri Bot. Gard. 74: 149. (1987) Spach: Nouv. Ann. Mus. Hist. Nat. 4: 348. (1836)
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