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large-flower evening-primrose

Howard's evening-primrose

Habit Herbs biennial, often appearing glabrous to naked eye, usually sparsely to moderately strigillose and villous with pustulate, translucent hairs proximal to inflorescence, pustules not red (in fresh material), inflorescence glabrous, glandular puberulent, or strigillose and glandular puberulent. Herbs acaulescent or sometimes caulescent, moderately to densely strigillose and glandular puberulent, sometimes also sparsely to moderately hirsute; from a taproot, sometimes lateral roots producing adventitious shoots.
Stems

erect, red on proximal parts, usually green on distal ones, rarely red throughout, unbranched or with branches obliquely arising from rosette and secondary branches arising from main stem, 100–300(–400) cm.

(when present) ascending, longer ones becoming decumbent, leafy, sometimes densely so, 0–10(–30) cm.

Leaves

in a basal rosette and cauline, basal 18–32 × (2–)3–6.5 cm, cauline 6–20 × 1.5–6.5 cm;

blade soft and thin, bright green, usually flat, rarely undulate, narrowly oblanceolate to narrowly obovate, or narrowly elliptic to elliptic, sometimes narrowly ovate distally, margins bluntly dentate or subentire, teeth widely spaced, sometimes sinuate-dentate proximally or lobed;

bracts usually caducous.

in a basal rosette, sometimes also cauline, (6–)8.5–17(–23) × (0.5–)1–2(–3) cm;

petiole 2–7.5 cm;

blade usually oblanceolate, elliptic to narrowly oblong, rarely lanceolate, margins often undulate, entire or remotely and irregularly pinnately lobed mostly in proximal 1/2, rarely more regularly pinnately lobed and lobing extending to distal 1/2, sinuses usually extending less than 1/2 to midrib, lobes triangular to oblong or linear, (1–)4–9(–13) mm, apex acute to obtuse.

Inflorescences

erect, often with secondary or tertiary branches just proximal to main one.

Flowers

opening near sunset;

buds erect, 5–9 mm diam., with free tips terminal, erect, 2–9 mm;

floral tube 35–55 mm;

sepals yellowish green or flushed with red, 22–46 mm;

petals yellow to pale yellow, fading pale yellowish white, very broadly obcordate or obovate, (25–)30–45 mm;

filaments 18–27 mm, anthers 10–15 mm, pollen 90–100% fertile;

style 57–90 mm, stigma exserted beyond anthers at anthesis.

usually 1 or 2, rarely more, opening per day near sunset, strongly and sweetly scented;

buds with unequal free tips 1–3(–4) mm;

floral tube (43–)60–110(–125) mm;

sepals (30–)35–60(–80) mm;

petals brilliant yellow, fading deep red, drying deep reddish purple to reddish brown, usually broadly obovate, rarely subrhombic, (30–)40–60(–73) mm, sometimes with a terminal tooth;

filaments (19–)25–38 mm, anthers 10–17 mm;

style(90–)110–145(–165) mm, stigma exserted beyond anthers at anthesis.

Capsules

erect or slightly spreading, dull green when dry, narrowly lanceoloid to narrowly ovoid, 15–35 × 3.5–5.5 mm, free tips of valves 0.5–2.5 mm.

leathery, ovoid, narrowly ovoid, or narrowly lanceoloid to broadly ellipsoid, winged, wings (2–)4–7(–11) mm wide, body (20–)25–50(–80) × 4–6 mm, dehiscent 1/4–1/3 their length;

pedicel 2–6 mm.

Seeds

1–1.7 × 0.6–1.2 mm.

numerous, usually in 1 row per locule, rarely in 2 rows toward base, obovoid to subcuboid, 3–8 × 2.5–3.5 mm.

2n

= 14.

= 28, 42, 56.

Oenothera grandiflora

Oenothera howardii

Phenology Flowering Jul–Aug(–Sep). Flowering May–Jul.
Habitat Scattered, presumably relictual populations on chalky bluffs, loose sand over limestone, along streams, marshes, ditches, roadsides. Open or rocky areas, in shale, fine-textured sandstones, clays, gypsum, or limestone from High Plains grasslands, open sites in pinyon-juniper woodlands, ponderosa pine-Douglas fir forests.
Elevation 20–600 m. (100–2000 ft.) (1000–)1500–2300(–3000) m. ((3300–)4900–7500(–9800) ft.)
Distribution
from FNA
AL; FL; MS; NC; SC; TN
[BONAP county map]
from FNA
CO; KS; NV; UT; WY
[WildflowerSearch map]
[BONAP county map]
Discussion

Oenothera grandiflora has a scattered distribution, from the eastern half of Mississippi and Alabama, east to Tennessee (Franklin and Marion counties), North Carolina (Cherokee, Macon, Martin, Moore, New Hanover, Sampson, and Swain counties), South Carolina (Oconee, Spartanburg, and Sumter counties), and Florida (Alachua, Escambia, Franklin, Lake, Leon, Polk, Putnam, and Santa Rosa counties). Collections from southern Canada, New York, Pennsylvania, Vermont, and West Virginia almost certainly represent cultivated plants, garden escapes, or adventive populations, and the single locality from central Kentucky also may be an introduction; it is sometimes a colonizer in disturbed sites such as along roads.

Oenothera grandiflora has plastome III and a BB genome composition. As summarized by W. Dietrich et al. (1997), some populations of O. grandiflora seem to be entirely or mostly composed of self-incompatible individuals, whereas others consist of self-compatible plants. This is an extremely uncommon phenomenon within a single species of Oenothera; the only other species known to exhibit mixed populations of self-incompatible and self-compatible individuals is O. primiveris.

Oenothera grandiflora Lamarck 1798, being a later homonym of O. grandiflora L’Héritier 1789, pertains here.

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

Oenotherahowardii is known from three disjunct areas: three collections on the High Plains (Baca and Otero counties, Colorado, and Hamilton County, Kansas); open yucca-juniper grassland, rocky slopes or disturbed areas on shale substrates along the Colorado counties of Boulder, Denver, Jefferson, and Larimer, and just over the state line in Wyoming; and, common to scattered, mostly on rocky slopes but also in shaded canyon sites on fine-textured red sandstones, clays, gypsum, chalky white degraded limestone or limestone in pinyon-juniper woodland to ponderosa pine-Douglas fir forest in southern Utah and eastern Nevada.

A. Nelson intended to publish Lavauxia howardii as a new combination and base it on Oenothera howardii M. E. Jones (1893), which was not validly published at the time, but inadvertently published L. howardii as a new species. Oenothera howardii (A. Nelson) W. L. Wagner is an isonym.

(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. 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. fruticosa, O. gaura, O. gayleana, O. glaucifolia, O. glazioviana, 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. 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. 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. biennis var. grandiflora, O. grandiflora var. glabra, O. grandiflora var. pubescens, O. lamarckiana, O. spectabilis Lavauxiahowardii a.
Name authority L’Héritier in W. Aiton: Hort. Kew. 2: 2. (1789) (A. Nelson) M. E. Jones ex Prain in B. D. Jackson et al.: Index Kew., suppl. 3: 121. (1908) — (as howardi)
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