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shale barren evening primrose

Cleland's evening primrose

Habit Herbs biennial or short-lived perennial, strigillose and sparsely to moderately villous, hairs sometimes pustulate, pustules with green or red bases, inflorescence glabrous or sparsely glandular puberulent, sometimes also sparsely villous. Herbs biennial, densely to sometimes sparsely strigillose, or also sparsely glandular puberulent distally.
Stems

erect to ascending, green or red, unbranched or with branches obliquely arising from rosette or in distal 1/2 of main stem.

sometimes with lateral branches arising obliquely from rosette, 20–70(–100) cm.

Leaves

in a basal rosette and cauline, basal 7–25 × 0.7–2 cm, cauline 6–13 × 0.4–1 cm;

blade dark green, somewhat glossy, very narrowly oblanceolate to narrowly oblanceolate, linear-elliptic, lanceolate, or nearly linear, margins flat, entire or remotely and bluntly dentate, sometimes with larger teeth near base;

bracts persistent.

in a basal rosette and cauline, basal 5–16 × 0.5–1.5 cm, cauline 2–12 × 0.5–2 cm;

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

bracts slightly longer than capsule they subtend.

Inflorescences

curved with ascending tip, unbranched.

dense, without lateral branches, mature buds usually not overtopping spike apex.

Flowers

opening near sunset;

buds erect, 4–8 mm diam., with free tips subterminal, divergent and hornlike, 3–9 mm;

floral tube 32–52 mm;

sepals yellowish green to yellow, sometimes flushed with red, especially at apex, 27–38 mm;

petals yellow to pale yellow, fading pale yellow to pale yellowish orange, very broadly obcordate or obovate, 25–42 mm;

filaments 20–27 mm, anthers 9–13 mm, pollen 90–100% fertile;

style 60–85 mm, stigma exserted beyond anthers at anthesis.

2–several per spike opening per day near sunset;

buds erect, with free tips erect, 0.5–2 mm;

floral tube slightly curved upward to± straight, 15–40 mm;

sepals 6–13 mm;

petals yellow, broadly elliptic to rhombic-ovate, 5–16 mm;

filaments 4–18 mm, anthers 2–3.5 mm, pollen ca. 50% fertile;

style 20–40 mm, stigma surrounded by anthers at anthesis.

Capsules

spreading at nearly a right angle to stem, curved upward, sometimes secund, dull green or rusty brown when dry, narrowly lanceoloid to lanceoloid, 20–40 × 4–6 mm, free tips of valves 1–2 mm.

narrowly lanceoloid, 10–20 ×2–3 mm.

Seeds

1.3–1.9 × 0.7–1.1 mm.

brown, sometimes flecked with dark red spots, ellipsoid, 1–1.9 × 0.4–0.8 mm.

2n

= 14.

= 14.

Oenothera argillicola

Oenothera clelandii

Phenology Flowering (Jun–)Jul–Oct. Flowering Jun–Aug(–Sep).
Habitat Open sites on Devonian Brallier shale slopes, barrens, outcrops or adjacent roadsides in mid-Appalachian Allegheny Mountains. Fields, prairies, sandy soil.
Elevation 150–700 m. (500–2300 ft.) 150–300 m. (500–1000 ft.)
Distribution
from FNA
MD; PA; VA; WV
[BONAP county map]
from FNA
AR; IA; IL; IN; KY; MI; MN; MO; NJ; NY; VA; WI; ON
[WildflowerSearch map]
[BONAP county map]
Discussion

Oenothera argillicola is one of eight angiosperm species restricted to the Devonian Brallier shale barrens, but among them only O. argillicola and Trifolium virginicum occur throughout the shale barren region. Oenothera argillicola has plastome V and a CC genome composition.

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

Oenothera clelandii is a PTH species and forms a ring of 14 chromosomes in meiosis, and is self-compatible and autogamous (W. Dietrich and W. L. Wagner 1988). Some localities in the easternmost states may represent introductions, primarily occurring in disturbed areas along roads and railroad lines.

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

Source FNA vol. 10. FNA vol. 10.
Parent taxa Onagraceae > subfam. Onagroideae > tribe Onagreae > Oenothera > sect. Oenothera > subsect. Oenothera Onagraceae > subfam. Onagroideae > tribe Onagreae > Oenothera > sect. Oenothera > subsect. Candela
Sibling taxa
O. acutissima, O. albicaulis, 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. 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. 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
Synonyms O. argillicola var. pubescens
Name authority Mackenzie: Torreya 4: 56. (1904) W. Dietrich, P. H. Raven & W. L. Wagner: Ann. Missouri Bot. Gard. 70: 196. (1983)
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