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Fendler evening primrose, Hartweg's sundrops

beakpod evening primrose, spotted evening-primrose

Habit Herbs perennial, sometimes suffrutescent, strigillose, glandular puberulent, glabrous, hirtellous, or short-pilose; from a stout taproot. Herbs low, forming clumps 10–50 cm diam., densely strigillose throughout; from a taproot, lateral roots producing adventitious shoots.
Stems

1–many, erect to ascending, unbranched to densely branched, 4–60 cm.

many-branched from base, leafy, (10–)15–25(–38) cm.

Leaves

0.3–6.5 × 0.04–1.2 cm, sometimes fascicles of small leaves 0.1–1.5 cm present in non-flowering axils;

petiole 0–0.2 cm;

blade elliptic, lanceolate, linear, or filiform to ovate or oblanceolate, usually not much reduced distally, proximalmost leaves sometimes obovate to spatulate, base attenuate to obtuse, truncate, or subcordate, sometimes clasping, margins entire or serrate, often undulate, apex acute.

cauline, (0.3–)0.6–1.5(–2.5) × (0.05–)0.15–0.4(–0.6) cm, fascicles of small leaves 0.2–0.6 cm often present in non-flowering axils;

petiole 0–0.1 cm;

blade lanceolate to linear, base cuneate, apex acute.

Flowers

usually 1 per stem opening per day in afternoon or near sunset;

buds with free tips 0.5–6 mm;

floral tube 16–50(–60) mm, funnelform in distal 1/2 or less;

sepals 7–28 mm;

petals yellow, fading pale pinkish or pale purple, 10–35 mm;

filaments 4–13 mm, anthers 5–13 mm, pollen 85–100% fertile;

style 25–65(–75) mm, stigma yellow, quadrangular, usually exserted beyond anthers.

several opening per day near sunset;

buds usually without free tips, rarely free tips 0.2–0.3 mm;

sepals (7–)8–12 mm;

petals pink, rarely white, streaked or flecked with red, fading bright purple, (8–)10–17 mm;

filaments 6–8 mm, anthers often with red longitudinal stripe, 3–6 mm;

style (16–)22–27 mm, stigma exserted beyond anthers at anthesis.

Capsules

6–40 × 2–4 mm, hard, promptly dehiscent throughout their length.

woody, ovoid, narrowly winged, wings 0.8–1.5 mm wide, (7–)9–12(–14) × 2–4 mm (excluding wings), abruptly constricted to a conspicuous, sterile beak, (2–)3–4.5 mm, indehiscent;

sessile.

Seeds

obovoid, 1–2.5 mm.

asymmetrically cuneiform or oblanceoloid, 1.2–1.5 × 0.4–0.5 mm.

2n

= 14, 28.

= 14.

Oenothera hartwegii

Oenothera canescens

Phenology Flowering May–Aug.
Habitat Prairie depressions, playas, margins of ditches, temporary wet areas.
Elevation (400–)700–1800 m. ((1300–)2300–5900 ft.)
Distribution
from USDA
c United States; sw United States; n Mexico
[WildflowerSearch map]
[BONAP county map]
from FNA
CO; KS; NE; NM; OK; TX; WY
[WildflowerSearch map]
[BONAP county map]
Discussion

Subspecies 5 (5 in the flora).

Oenothera hartwegii consists of five intergrading subspecies, which are generally locally common on rocky, sandy, gypsum, or limestone soil in arid to relatively mesic open areas, in southeastern Colorado, southwestern Kansas, western Oklahoma, Texas (except eastern part), New Mexico, southeastern and east-central Arizona, and in Mexico from Chihuahua, northern Coahuila, and northwestern Tamaulipas south to Aguascalientes. H. F. Towner (1977) found that O. hartwegii is self-incompatible and usually vespertine; two of the subspecies (filifolia and maccartii) open early in the afternoon and are pollinated both day and evening.

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

Oenothera canescens is restricted to prairie depressions, playas, ditch margins, and other places of temporary water in the High Plains of the western United States from Goshen County, Wyoming, southeast to Hayes County, Nebraska, south through eastern Colorado, the eastern tier of counties in New Mexico, western Kansas, and to Garza and Dawson counties in the Texas Panhandle; also disjunct populations from Chautauqua, Sedgwick, and Stafford counties, Kansas.

The illegitimate names Gaurella guttulata (Geyer ex Hooker) Small, G. canescens (Torrey & Frémont) Cockerell, and Gauropsis guttulata (Geyer ex Hooker) Cockerell pertain here.

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

Key
1. Leaves (except proximalmost): blade base truncate or subcordate and clasping; plants densely pubescent with mixture of hair types, but always short-pilose and usually also hirtellous, sometimes also strigillose, especially on leaves, or glandular puberulent distally.
subsp. pubescens
1. Leaves: blade base attenuate or obtuse; plants glabrous, sparsely strigillose, or glandular puberulent.
→ 2
2. Plants usually glabrous throughout, sometimes glandular puberulent on distal parts, especially on ovary.
subsp. fendleri
2. Plants strigillose and/or glandular puberulent, especially on distal parts.
→ 3
3. Plants glandular puberulent throughout, more densely so on distal parts, sometimes also sparsely strigillose on ovary and leaves; leaf blades filiform to narrowly lanceolate.
subsp. filifolia
3. Plants usually strigillose, rarely glandular puberulent; leaf blade narrowly lanceolate to oblanceolate, sometimes linear.
→ 4
4. Leaf blades narrowly lanceolate, sometimes linear, margins entire or shallowly and sparsely serrulate, sometimes undulate; plants sparsely to densely strigillose throughout.
subsp. hartwegii
4. Leaf blades usually narrowly lanceolate to lanceolate or oblanceolate, rarely linear, margins subentire or serrulate, usually crinkled-undulate; plants usually sparsely strigillose, sometimes glandular puberulent.
subsp. maccartii
Source FNA vol. 10. FNA vol. 10.
Parent taxa Onagraceae > subfam. Onagroideae > tribe Onagreae > Oenothera > sect. Calylophus > subsect. Salpingia Onagraceae > subfam. Onagroideae > tribe Onagreae > Oenothera > sect. Gauropsis
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. glaucifolia, O. glazioviana, O. grandiflora, O. grandis, O. harringtonii, 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. 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. 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. hartwegii subsp. fendleri, O. hartwegii subsp. filifolia, O. hartwegii subsp. hartwegii, O. hartwegii subsp. maccartii, O. hartwegii subsp. pubescens
Synonyms Calylophus hartwegii, Galpinsia hartwegii, Salpingia hartwegii Gaurella canescens, Megapterium canescens, O. guttulata
Name authority Bentham: Pl. Hartw., 5. (1839) — (as hartwegi) Torrey & Frémont in J. C. Fremont: Rep. Exped. Rocky Mts., 315. (1845)
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