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narrowleaf evening primrose

narrow-leaf evening-primrose

Habit Herbs moderately to densely strigillose, and/or sometimes glandular puberulent or villous; from fibrous or, sometimes, slightly fleshy rootstock or producing rhizomes. Herbs perennial, moderately to densely strigillose and/or villous, glandular puberulent, or glabrous; from fibrous roots, not or rarely producing rhizomes.
Stems

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

Leaves

basal 3–10 × 0.5–2 cm, petiole 1–4 cm, blade oblanceolate to obovate, margins subentire or weakly and remotely denticulate;

cauline 2–6(–8) × 0.1–1(–1.7) cm, petiole 0.2–2(–4) cm, blade linear, lanceolate to oblanceolate, narrowly elliptic, or narrowly ovate, margins subentire or weakly and remotely denticulate.

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.

Inflorescences

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

Flowers

buds with free tips 0.5–1(–6) mm, usually connivent, sometimes spreading;

floral tube5–15 mm;

sepals 5–20 mm;

petals (8–)15–25 mm.

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.

Capsules

clavate to oblong-clavate, widest distal to middle, angled, rarely narrowly winged, (5–)10–17(–20) × (2–)3–4 mm, stipe 3–10 mm;

sessile.

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.

Seeds

1 × 0.5 mm.

2n

= 28, 42.

Oenothera fruticosa subsp. fruticosa

Oenothera fruticosa

Phenology Flowering Apr–Aug(–Sep).
Habitat Open habitats, meadows, stream margins, edges of woods, open woods, margins of freshwater or saltwater marshes, stabilized sand dunes, roadsides, partially disturbed habitats.
Elevation 0–500(–1100) m. (0–1600(–3600) ft.)
Distribution
from FNA
AL; AR; CT; DC; DE; FL; GA; IL; IN; KY; LA; MA; MD; MO; MS; NC; NY; OH; OK; PA; SC; TN; VA; WV
[BONAP county map]
from USDA
e North America; c North America
[WildflowerSearch map]
[BONAP county map]
Discussion

Kneiffia suffruticosa Spach (1835) is an illegitimate substitution for Oenothera fruticosa, as is K. angustifolia Spach (1835) one for O. linearis Michaux, and O. linearis var. allenii Britton (1894) is one based on O. fruticosa var. humifusa.

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

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.)

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 > Oenothera fruticosa Onagraceae > subfam. Onagroideae > tribe Onagreae > Oenothera > sect. Kneiffia
Sibling taxa
O. fruticosa subsp. tetragona
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
Subordinate taxa
O. fruticosa subsp. fruticosa, O. fruticosa subsp. tetragona
Synonyms Kneiffia allenii, K. arenicola, K. brevistipata, K. charlesii, K. fruticosa var. humifusa, K. fruticosa var. unguiculata, K. linearis, K. longipedicellata, K. semiglandulosa, K. subglobosa, K. tetragona var. longistipata, K. velutina, O. fruticosa var. eamesii, O. fruticosa var. goodmanii, O. fruticosa var. humifusa, O. fruticosa var. linearifolia, O. fruticosa var. linearis, O. fruticosa var. microcarpa, O. fruticosa var. subglobosa, O. fruticosa var. unguiculata, O. fruticosa var. vera, O. linearis, O. linearis var. eamesii, O. longipedicellata, O. subglobosa, O. subglobosa var. arenicola, O. tetragona var. brevistipata, O. tetragona var. longistipata, O. tetragona var. sharpii, O. tetragona var. velutina, O. unguiculata Kneiffia fruticosa
Name authority unknown Linnaeus: Sp. Pl. 1: 346. (1753)
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