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cut-leaf evening-primrose, southern evening primrose

Fendler evening primrose, Hartweg's sundrops

Habit Herbs annual, sparsely to moderately strigillose, sometimes also villous, sometimes also becoming glandular puberulent distally. Herbs perennial, sometimes suffrutescent, strigillose, glandular puberulent, glabrous, hirtellous, or short-pilose; from a stout taproot.
Stems

erect to ascending, unbranched to much branched, 5–50 cm.

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

Leaves

in a basal rosette and cauline, basal 4–15 × 1–3 cm, cauline 2–10 × 0.5–3.5 cm;

blade green, narrowly oblanceolate to narrowly elliptic or narrowly oblong, margins usually dentate or deeply lobed;

bracts spreading, flat.

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.

Flowers

usually 1 opening per day near sunset;

buds erect, with free tips erect, 0.3–3 mm;

floral tube 12–35 mm;

sepals 5–15 mm;

petals yellow, fading orange or reddish tinged, broadly obovate or obcordate, 5–22 mm;

filaments 3–14 mm, anthers 4–5 mm, pollen ca. 50% fertile;

style 20–50 mm, stigma surrounded by anthers at anthesis.

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.

Capsules

cylindrical, sometimes slightly enlarged toward apex, 20–50 × 2–4 mm.

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

Seeds

ellipsoid to subglobose, 0.9–1.8 × 0.4–0.9 mm.

obovoid, 1–2.5 mm.

2n

= 14.

= 14, 28.

Oenothera laciniata

Oenothera hartwegii

Phenology Flowering (Feb–)Apr–Sep(–Oct).
Habitat introduced nearly worldwide in temperate and subtropical areas..
Elevation 0–1000(–1300) m. (0–3300(–4300) ft.)
Distribution
from FNA
AL; AR; CA; CT; DC; DE; FL; GA; IA; IL; IN; KS; KY; LA; MA; MD; ME; MI; MN; MO; MS; NC; ND; NE; NJ; NM; NY; OH; OK; PA; RI; SC; SD; TN; TX; VA; VT; WI; WV; WY [Introduced nearly worldwide in temperate and subtropical areas]
[WildflowerSearch map]
[BONAP county map]
from USDA
c United States; sw United States; n Mexico
[WildflowerSearch map]
[BONAP county map]
Discussion

Oenothera laciniata is a PTH species and forms aring of 14 chromosomes in meiosis, and is self-compatible and autogamous (W. Dietrich and W. L. Wagner 1988).

Oenothera laciniata is known in New Mexico from Doña Ana and Roosevelt counties from non-montane habitats and thus do not appear to represent O. pubescens; however, a few collections from Brewster and Jeff Davis counties, Texas, reported by W. Dietrich and W. L. Wagner (1988) as O. laciniata appear to represent collections of O. pubescens. Dietrich and Wagner found that O. laciniata hybridizes not only with O. grandis, but also with O. drummondii subsp. drummondii, O. humifusa, and O. mexicana. It is naturalized nearly worldwide in temperate and subtropical areas.

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

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.)

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. Oenothera > subsect. Raimannia Onagraceae > subfam. Onagroideae > tribe Onagreae > Oenothera > sect. Calylophus > subsect. Salpingia
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. hartwegii, O. havardii, O. heterophylla, O. hispida, O. howardii, O. humifusa, O. jamesii, O. kunthiana, 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. 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 O. minima, O. repanda, O. sinuata, O. sinuata var. minima, Onagra sinuata, Raimannia laciniata Calylophus hartwegii, Galpinsia hartwegii, Salpingia hartwegii
Name authority Hill: Veg. Syst. 12(app.): 64, plate 10. (1767) Bentham: Pl. Hartw., 5. (1839) — (as hartwegi)
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