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lizard-tail, small-flower bee-blossom, small-flower gaura, velvet weed

Habit Herbs annual, strigillose, glandular puberulent, and long-villous; from heavy taproot, 2–4 cm diam. Herbs perennial, sparsely strigillose, becoming glabrate distally, usually also glandular puberulent distally; from a somewhat fleshy rootstock, forming adventitious roots where submerged.
Stems

erect, unbranched or many-branched distally, (20–)30–200(–300) cm.

erect or ascending, usually many-branched throughout, proximal branches often somewhat spongy, 50–120 cm.

Leaves

in a basal rosette and cauline, basal 4–15 × 1.5–3 cm, petiole 0–1.8 cm, blade broadly oblanceolate, margins sinuate-dentate to dentate;

cauline 2–13 × 0.5–5 cm, petiole 0–2 cm, blade narrowly elliptic to narrowly ovate, margins sinuate-dentate to dentate.

in a basal rosette and cauline, softly succulent, 4–13.5 × 0.8–2.1 cm, petiole 0–1.5 cm, blade lanceolate to elliptic-lanceolate, margins remotely denticulate.

Inflorescences

relatively long, dense.

erect, flowers in axils of distalmost few nodes.

Flowers

4-merous, nearly actinomorphic, opening near sunset;

floral tube 1.5–5 mm;

sepals 2–3.5 mm;

petals white, fading pale to dark pink, slightly unequal, oblong-obovate to elliptic-oblanceolate, 1.5–3 mm, abruptly clawed;

filaments 1.5–3 mm, anthers 0.5–1 mm, pollen 85–100% fertile;

style 3–9 mm, stigma surrounded by anthers at anthesis.

opening near sunrise;

buds with free tips 0.5–2(–5) mm, erect to spreading;

floral tube 14–20 mm;

sepals 20–30 mm;

petals bright yellow, fading pale pink or lavender, 16–27 mm;

filaments 10–15 mm, anthers 7–8 mm, pollen 85–100% fertile;

style 15–30 mm, stigma exserted beyond anthers at anthesis.

Capsules

fusiform, terete, weakly angled in distal 1/3, angles becoming broad and rounded in proximal part, 5–11 × 1.5–3 mm, tapering abruptly toward base;

sessile.

oblong-clavate to oblong-ellipsoid, 4-angled or 4-winged, and wings 0.1–0.2 mm, 7–15 × 4–6 mm, stipe 2–5 mm;

sessile.

Seeds

3 or 4, reddish brown, 2–3 × 1–1.5 mm.

0.8 × 0.4 mm.

2n

= 14.

= 56.

Oenothera curtiflora

Oenothera riparia

Phenology Flowering (Feb–)Apr–Oct. Flowering May–Jul.
Habitat Rocky prairie slopes, woodlands, along streams, roadsides, disturbed areas. Isolated colonies in or at edge of water in marshes or slow-running rivers, apparently with at least some tidal influence.
Elevation 10–2800 m. (0–9200 ft.) 0–10 m. (0–0 ft.)
Distribution
from FNA
AL; AR; AZ; CA; CO; FL; GA; IA; ID; IL; IN; KS; KY; LA; MA; MD; MN; MO; MT; NE; NM; NV; OK; OR; SC; SD; TN; TX; UT; VA; WA; WY; Mexico (Baja California, Chihuahua, Coahuila, Durango, Nuevo León, Sinaloa, Zacatecas) [Introduced in South America (Argentina), Asia (China, Japan), Australia]
[WildflowerSearch map]
[BONAP county map]
from FNA
GA; NC; SC; VA
Discussion

Oenothera curtiflora is self-compatible and autogamous (P. H. Raven and D. P. Gregory 1972[1973]). Sometimes it is apparently a biennial. The species is native to grassland regions and open areas across much of interior North America. The full extent of its indigenous range is not clear and collections from the eastern half of the United States (Alabama, Florida, Georgia, Indiana, Massachusetts, and Tennessee) and California may be more recent introductions. Gaura mollis Nuttall ex Torrey 1827 is an isonym of G. mollis E. James 1822, a suppressed name.

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

Oenothera riparia has not been accepted as a distinct species for a long time. The conservative approach used by G. B. Straley (1977) is here followed in recognizing a broadly delimited O. fruticosa, except that the very distinctive coastal tidal-freshwater semi-aquatic octoploid populations (Straley 1982) are recognized as O. riparia. Plants of these coastal populations, which occur from southern Virginia to North Carolina, are more robust, more branched, and less pubescent than those of the two subspecies of O. fruticosa, and have slightly succulent leaves and more prominent adventitious roots (Straley 1982; D. Boufford, pers. comm.). Further field studies and cytological analyses are needed to fully understand the geographical and ecological limits of O. riparia and confirm that it is strictly an octoploid species. K. N. Krakos et al. (2014) determined that Oenothera riparia is self-incompatible and is pollinated by bees (Bombus, Lassioglossum, Megachile, Parallelia, Xylocopa, and Zale).

(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. Gaura > subsect. Schizocarya Onagraceae > subfam. Onagroideae > tribe Onagreae > Oenothera > sect. Kneiffia
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. 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. 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. 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 Gaura parviflora, G. australis, G. hirsuta, G. micrantha, G. parviflora var. lachnocarpa, Schizocarya micrantha Kneiffia riparia, O. tetragona var. riparia
Name authority W. L. Wagner & Hoch: Syst. Bot. Monogr. 83: 211. (2007) Nuttall: Gen. N. Amer. Pl. 1: 247. (1818)
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