The green links below add additional plants to the comparison table. Blue links lead to other Web sites.
enable glossary links

threadleaf evening-primrose, threadleaf sundrop

southern beeblossom

Habit Herbs annual, caulescent, strigillose or glabrous, also often glandular puberulent, especially distally; from a sparsely branched taproot. Herbs annual, glabrate, strigillose, and/or hirtellous; from taproot.
Stems

unbranched or with many ascending branches arising near base, erect, 10–50 cm.

usually unbranched, sometimes several-branched from base, 60–180 cm.

Leaves

in a basal rosette and cauline, basal 1–2(–4) × 0.2–0.6 cm, petiole 0.2–1(–1.5) cm, blade ovate to obovate or narrowly elliptic;

cauline 1–4 × less than 0.1 cm, sessile, blade linear or filiform.

in a basal rosette and cauline, 0.8–13 × 0.1–1.6 cm;

blade often red-blotched, narrowly lanceolate to narrowly oblanceolate, margins slightly to conspicuously sinuate-dentate.

Flowers

usually 1–3 opening per day near sunrise;

buds without free tips;

sepals 1.5–2 mm;

petals bright yellow, fading pink, obcordate to obovate, 3–5(–7) mm;

filaments 1–2 mm, anthers 0.5–1 mm;

style 1–2 mm, stigma surrounded by anthers at anthesis.

3 or 4-merous, often mixed on a single plant, zygomorphic, opening near sunset;

floral tube 3–8 mm;

sepals 2.5–8 mm;

petals white, fading pink, narrowly elliptic-obovate, 4.5–8 mm;

filaments 2.5–6 mm, anthers 0.5–2 mm, pollen 90–100% fertile;

style 7.5–19 mm, stigma surrounded by or slightly exserted beyond anthers.

Capsules

ellipsoid-rhombic to subglobose, 4-angled, 4–6(–10) × 1.5–3 mm, stipe 0–4 mm, valve midrib raised at distal end, indehiscent or tardily dehiscent distally;

sessile.

ellipsoid or ovoid, 3-(or 4-)angled, 5–9 × 2–3 mm;

sessile.

Seeds

clustered in each locule, ovoid, surface minutely papillose, 1 × 0.5 mm.

2–4, yellowish to light brown, 1.2–2.3 × 0.8–1.1 mm.

2n

= 14.

= 14.

Oenothera linifolia

Oenothera simulans

Phenology Flowering Apr–Jun(–Aug). Flowering (Feb–)May–Sep(–Nov).
Habitat Prairies, open woodlands, open rocky and sandy sites, roadsides. Sandy soil in open woodlands, fields, roadsides, primarily in outer Coastal Plain.
Elevation 0–400 m. (0–1300 ft.) 0–10 m. (0–0 ft.)
Distribution
from FNA
AL; AR; FL; GA; IL; KS; KY; LA; MO; MS; NC; OK; SC; TN; TX
[WildflowerSearch map]
[BONAP county map]
from FNA
FL; GA; NC; SC
[WildflowerSearch map]
[BONAP county map]
Discussion

Kneiffia linearifolia Spach (1835) is an illegitimate name based on Oenothera linifolia.

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

Oenothera simulans occurs along the Coastal Plain from Cape Hatteras, North Carolina, southward and throughout Florida. It is self-compatible and autogamous (P. H. Raven and D. P. Gregory 1972[1973]). The species occasionally persists through mild winters in the southern part of its range, appearing biennial.

Gaura fruticosa Jacquin 1786, not G. fruticosa Loefling 1758, is an illegitimate later homonym that pertains here.

(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. Peniophyllum 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. havardii, O. heterophylla, O. hispida, O. howardii, O. humifusa, O. jamesii, O. kunthiana, O. laciniata, O. lavandulifolia, O. lindheimeri, 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. 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 Kneiffia linifolia, O. linifolia var. glandulosa, Peniophyllum linifolium Gaura simulans, G. angustifolia, G. angustifolia var. eatonii, G. angustifolia var. simulans, G. angustifolia var. strigosa, G. eatonii
Name authority Nuttall: J. Acad. Nat. Sci. Philadelphia 2: 120. (1821) (Small) W. L. Wagner & Hoch: Syst. Bot. Monogr. 83: 213. (2007)
Web links