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narrow-leaf evening-primrose

El Paso evening primrose

Habit Herbs perennial, moderately to densely strigillose and/or villous, glandular puberulent, or glabrous; from fibrous roots, not or rarely producing rhizomes. Herbs acaulescent or caulescent, densely strigillose and glandular puberulent distally; from a taproot.
Stems

erect to decumbent, branched or unbranched, (10–)30–80 cm.

densely leafy, 4–20 cm.

Leaves

in a basal rosette and cauline, rosette usually withered by anthesis, surfaces sometimes glaucous, especially abaxially, basal 3–12 × 0.5–3 cm, petiole 1–4 cm, blade oblanceolate to obovate, margins subentire, dentate, or denticulate, sometimes undulate;

cauline 2–6(–11) × (0.1–)0.5–2(–5) cm, petiole 0.1–2(–6) cm, blade linear, lanceolate to oblanceolate, narrowly elliptic, or ovate, margins subentire or dentate or denticulate, sometimes undulate.

in a basal rosette, sometimes also cauline, 5–16 × (0.2–)0.3–0.5(–0.7) cm;

petiole 0.6–3.5 cm;

blade linear to narrowly lanceolate, margins entire or sometimes proximal 1/2 of blade remotely lobed, apex long-attenuate, acute to rounded.

Inflorescences

usually erect, rarely nodding, flowers in axils of distalmost few nodes.

Flowers

opening near sunrise;

buds with free tips 0.5–8(–13) mm, connivent, sometimes spreading;

floral tube 5–20 mm;

sepals 5–20 mm;

petals pale to bright yellow, fading pale pink, orangish pink, or yellow, (8–)15–25(–30) mm;

filaments 5–15 mm, anthers 4–7 mm, pollen 85–100% fertile;

style 12–20 mm, stigma exserted beyond anthers at anthesis.

usually 1–3, rarely more, opening per day near sunset, weakly scented;

buds with unequal free tips 0.7–1.2 mm;

floral tube (55–)75–100(–125) mm;

sepals 34–40 mm;

petals lemon-yellow, fading orange, drying lavender to purple, broadly obovate, 35–43 mm, sometimes with terminal tooth;

filaments 17–25 mm, anthers 14–17 mm;

style (85–)105–135(–143) mm, stigma exserted beyond anthers at anthesis.

Capsules

clavate to oblong-clavate or oblong-ellipsoid, 4-angled to 4-winged, (5–)10–17(–20) × (2–)3–4(–6) mm, stipe 0.1–10 mm;

sessile.

leathery, lanceoloid to ovoid, winged, wings 4–6 mm wide, body 25–30 × 8 mm, dehiscent 1/4–1/3 their length;

pedicel 1–2(–3) mm.

Seeds

1 × 0.5 mm.

numerous, usually in 2 distinct rows per locule, often reduced to 1 row near apex, rarely 1 row throughout, obovoid to subcuboid, 2.5–4 × 2.5–3.5 mm.

2n

= 42.

Oenothera fruticosa

Oenothera coryi

Phenology Flowering Apr–May.
Habitat Open grasslands, disturbed areas.
Elevation 300–1000 m. (1000–3300 ft.)
Distribution
from USDA
e North America; c North America
[WildflowerSearch map]
[BONAP county map]
from FNA
TX
[BONAP county map]
Discussion

Subspecies 2 (2 in the flora).

Oenothera fruticosa as delimited here is a polymorphic species. Previous classification of this group has undergone numerous reorganizations due to the difficulties in separating populations into discrete morphological taxa. In the past it has most frequently been treated as two species, O. fruticosa and O. tetragona Roth, often with a dozen or more infraspecific taxa recognized. The broad delimitation of G. B. Straley (1977) is followed here with one species consisting of two subspecies that appear to intergrade extensively across a wide area of overlap. Straley determined O. fruticosa to be self-incompatible and polyploid.

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

Oenothera coryi is known only from Baylor, Callahan, Knox, Nolan, Taylor, and Throckmorton counties in north-central Texas and Crosby and Garza counties in the Texas Panhandle.

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

Key
1. Capsules clavate to oblong-clavate, widest above middle; plants moderately to densely strigillose, and/or sometimes glandular puberulent or villous; leaf blade margins subentire or weakly and remotely denticulate.
subsp. fruticosa
1. Capsules oblong to oblong-ellipsoid, widest at middle; plants glandular puberulent or glabrous, sometimes villous or strigillose; leaf blade margins dentate to remotely denticulate.
subsp. tetragona
Source FNA vol. 10. FNA vol. 10.
Parent taxa Onagraceae > subfam. Onagroideae > tribe Onagreae > Oenothera > sect. Kneiffia Onagraceae > subfam. Onagroideae > tribe Onagreae > Oenothera > sect. Megapterium
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. 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. 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. fruticosa subsp. fruticosa, O. fruticosa subsp. tetragona
Synonyms Kneiffia fruticosa
Name authority Linnaeus: Sp. Pl. 1: 346. (1753) W. L. Wagner: Ann. Missouri Bot. Gard. 73: 475. (1986)
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