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Havard's evening primrose

prairie beeblossom

Habit Herbs compact to sprawling, strigillose; from a taproot, lateral roots producing adventitious shoots. Herbs annual, villous proximally, sparsely villous along veins and on margins, usually glabrate, sometimes strigillose distally; from taproot.
Stems

usually many-branched, sometimes unbranched, often twining among vegetation, sometimes rooting at nodes, 5–25(–70) cm.

ascending, usually well-branched from base and distally, rarely unbranched, 15–60 cm.

Leaves

in a basal rosette and cauline, basal usually quickly deciduous, (1–)2–5 × (0.2–)0.5–1.5 cm;

petiole 0–0.6 cm;

blade oblanceolate, linear-lanceolate to linear distally, margins few toothed to pinnately lobed to sinuate-dentate distally.

in a basal rosette and cauline, 1.5–8 × 0.2–0.6(–1.5) cm, blade very narrowly elliptic to oblanceolate or oblong-elliptic, margins entire or weakly sinuate-dentate.

Flowers

1–few opening per day near sunset;

buds often twisted, free tips coherent;

floral tube (37–)45–60(–65) mm;

sepals (16–)18–26(–30) mm;

petals lemon-yellow, fading orange-red to reddish purple, usually elliptic, sometimes oblanceolate, (18–)21–30(–32) mm;

filaments 15–18(–22) mm, anthers red, 6–13 mm;

style (55–)65–86(–94) mm, stigma exserted beyond anthers at anthesis.

3(or 4)-merous, zygomorphic, opening at sunset;

floral tube 4–5.5 mm;

sepals 4.5–6 mm;

petals white, fading pink, elliptic-obovate, 3.5–5 mm;

filaments 2–3.5 mm, anthers 1.5–3 mm, pollen 35–65% fertile;

style 9–10 mm, stigma surrounded by anthers.

Capsules

woody, narrowly ovoid to ovoid, 4-angled, 8–13(–16) × 3–4 mm, apex tapering to a short sterile beak 2–3 mm, valves with a prominent, broad midrib and capsule appearing 8-ribbed, tardily dehiscent ca. 1/3 capsule length.

narrowly obovoid, 3(or 4)-winged, furrowed between wings, 7–9 × 3–5 mm, narrowed at base;

sessile.

Seeds

2–2.5(–3.3) × 1.2–1.5 mm, sometimes with a small wing at distal end or a raised ridge along one longitudinal margin.

(1 or)2–5, yellowishto light brown, 1.5–3.5 × 1–1.5 mm.

2n

= 14, 28.

= 14.

Oenothera havardii

Oenothera triangulata

Phenology Flowering Apr–Oct. Flowering Apr–Jul.
Habitat In depressions, seasonally wet flats, stream banks, margins of irrigated fields, sandy or clay soil, among tufted grasses like Sporobolus wrightii, primarily in Chihuahuan Desert. Open, sandy sites.
Elevation 1300–2000 m. (4300–6600 ft.) 200–600 m. (700–2000 ft.)
Distribution
from FNA
AZ; TX; Mexico (Chihuahua, Durango, Sonora, Zacatecas)
[BONAP county map]
from FNA
OK; TX
[BONAP county map]
Discussion

Oenothera havardii ranges from Brewster and Presidio counties, Texas, and Cochise County, Arizona, south to Durango and Zacatecas, Mexico. W. L. Wagner (1984) found that O. havardii is self-incompatible and vespertine.

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

Oenothera triangulata is a PTH species and forms a ring of 14 chromosomes in meiosis. The species is self-compatible and autogamous (P. H. Raven and D. P. Gregory 1972[1973]). It may have been derived from hybridization between O. patriciae and O. suffulta. The species has a relatively narrow distribution across south-central Oklahoma and north-central Texas (Oklahoma in Cleveland, Comanche, Cotton, Grady, Oklahoma, Rogers, Stephens, and Tulsa counties; Texas in Archer, Baylor, Callahan, Clay, Coleman, Crosby, Eastland, Erath, Jones, Montague, Taylor, Throckmorton, Tom Greene, Wichita, Wilbarger, and Young counties).

(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. Paradoxus Onagraceae > subfam. Onagroideae > tribe Onagreae > Oenothera > sect. Gaura > subsect. Gaura
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. 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. 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. triloba, O. tubicula, O. villosa, O. wolfii, O. xylocarpa
Synonyms Hartmannia havardii, H. palmeri Gaura triangulata, G. hexandra var. triangulata, G. tripetala var. triangulata
Name authority S. Watson: Proc. Amer. Acad. Arts 20: 366. (1885) — (as havardi) (Buckley) W. L. Wagner & Hoch: Syst. Bot. Monogr. 83: 214. (2007)
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