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

bigfruit evening primrose, Missouri evening primrose, Ozark sundrop

linda tarde, scarlet beeblossom, scarlet evening-primrose, scarlet gaura, wild honeysuckle

Habit Herbs caulescent, strigillose or glabrous, sometimes glandular puberulent distally; from a stout taproot, sometimes lateral roots producing adventitious shoots. Herbs perennial, densely strigillose, sometimes also long-villous proximally, sometimes glabrate; from a deep, thick taproot, often with branching underground stems, or branching only at surface, these often becoming horizontal or nearly so and giving rise to new plants.
Stems

moderately leafy, (1–)4–40(–60) cm.

erect or ascending, usually many-branched, 10–120 cm.

Leaves

cauline, (2.8–)3.7–12.5(–17) × (0.1–)0.4–3(–4.5) cm;

petiole (0.4–)1–4(–6) cm;

blade linear, lanceolate-elliptic, elliptic to oblanceolate or suborbiculate, margins entire or conspicuously or inconspicuously denticulate or serrulate, sometimes undulate, apex usually acute, sometimes obtuse or retuse (subsp. incana).

in a basal rosette (but not present at flowering) and cauline, 0.7–6.5 × 0.1–1.5 cm, blade linear to narrowly elliptic, margins entire or remotely and coarsely serrate.

Flowers

usually 1 or 2, rarely more, opening per day near sunset, fading next morning, sometimes (subspp.

4-merous, zygomorphic, opening near sunset;

floral tube 4–11(–13) mm;

sepals 5–9(–10) mm;

petals white, fading salmon pink to scarlet-red, slightly unequal, obovate to elliptic-obovate or elliptic, 3–7(–8) mm, abruptly clawed;

filaments 3–6.5(–7) mm, anthers (2.5–)3–5(–5.5) mm;

style 10–22 mm, stigma exserted beyond anthers at anthesis.

Capsules

papery in age, narrowly ellipsoid to lanceoloid, sometimes twisted (subsp. fremontii), winged, wings (2–)10–28(–34) mm wide, body (13–)25–70(–115) × 2–9 mm, dehiscent 1/4–1/3 their length;

pedicel 1–12(–25) mm.

erect, pyramidal in distal 1/2 and abruptly constricted to terete proximal part, pyramidal part weakly or strongly angled, not conspicuously bulging at base, 4–9 × (1–)1.5–3 mm;

sessile.

Seeds

numerous, rarely as few as 8, in 1 row per locule, obovoid, (2–)3–5 × 1–2.3 mm.

(1–)3 or 4, light to reddish brown, 1.5–3 × 1–1.5 mm.

Macrocarpa

and oklahomensis) lasting for 2 days, weakly scented;

buds with unequal free tips 1–11(–15) mm;

floral tube (21–)35–140(–160) mm;

sepals (20–)25–65(–75) mm;

petals bright yellow, fading orange, reddish orange or mostly unchanged, obovate to very broadly obovate, (17–)25–65(–68) mm, usually with terminal notch and/or tooth, margin sometimes erose;

filaments 13–40(–44) mm, anthers 10–24(–25) mm;

style (45–)55–192 mm, stigma usually exserted beyond anthers at anthesis.

2n

= 14, 28, 42, 56.

Oenothera macrocarpa

Oenothera suffrutescens

Phenology Flowering Apr–Aug(–Nov).
Habitat Sandy or clay soil, often calcareous, desert shrublands to pinyon-juniper or oak woodlands, grasslands, disturbed areas.
Elevation 150–2000(–3000) m. (500–6600(–9800) ft.)
Distribution
from USDA
c United States; n Mexico; s United States
[WildflowerSearch map]
[BONAP county map]
from FNA
AZ; CA; CO; IA; IL; IN; KS; MI; MN; MO; MT; ND; NE; NM; NV; NY; OK; SD; TX; UT; WI; WY; AB; BC; MB; ON; SK; Mexico (Aguascalientes, Chihuahua, Coahuila, Durango, Guanajuato, Hidalgo, Jalisco, México, Nuevo León, Oaxaca, Puebla, San Luis Potosí, Sonora, Tamaulipas, Veracruz, Zacatecas); intro­duced in South America (Brazil); Europe (Wales)
[WildflowerSearch map]
[BONAP county map]
Discussion

Subspecies 5 (4 in the flora).

Oenotheramacrocarpa is variable and has differentiated extensively in the Great Plains region. Each of the five distinctive subspecies occupies a different geographical and ecological situation. Only subsp. mexicana W. L. Wagner from Coahuila, Mexico, occurs outside of the flora area. In general, the subspecies are sharply distinct and each is characterized by a number of features, including pubescence, leaf features, flower and floral tube size, and size and morphology of the capsules and seeds. The five entities are treated as subspecies primarily because of their complete interfertility and extensive intergradation in any area of marginal contact. Intermediates are known between subsp. macrocarpa and subspp. fremontii and oklahomensis and between subspp. incana and oklahomensis. There is also some evidence that suggests past hybridization between subspp. fremontii and incana although there is no present contact between them. All subspecies are self-incompatible.

Oenothera alata Nuttall (1818) is an illegitimate name based on O. macrocarpa and pertains here.

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

Oenothera suffrutescens is naturalized sporadically in southern California (Los Angeles, San Diego, Santa Barbara, and Ventura counties; although native in eastern part of the state), Illinois, Indiana, Michigan, New York, southern Ontario, and Wisconsin.

P. H. Raven and D. P. Gregory (1972[1973]) determined Oenothera suffrutescens to be self-incompatible and polyploid. It is known to form hybrids with O. calcicola and O. hispida.

Schizocarya kunthii Spach is an illegitimate name based on Gaura epilobioides that pertains here.

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

Key
1. Herbs glabrous.
→ 2
2. Leaf blades usually very broadly elliptic to suborbiculate, rarely oblanceolate or elliptic, 2–4.3 cm wide, margins usually entire, sometimes inconspicuously denticulate, usually flat, sometimes undulate.
subsp. incana
2. Leaf blades usually elliptic to lanceolate-elliptic, sometimes linear, (0.3–)0.8–2(–3) cm wide, margins usually conspicuously denticulate to serrulate, rarely subentire, usually undulate.
subsp. oklahomensis
1. Herbs strigillose.
→ 3
3. Bud free tips 1–2(–5) mm; petals (17–)25–33(–37) mm; floral tubes (21–)35–65(–80) mm; capsules often twisted, 13–30(–65) mm, wings 2–5(–9) mm wide.
subsp. fremontii
3. Bud free tips (4–)5–11(–12) mm; petals (25–)31–65(–68) mm; floral tubes (50–)70–140(–160) mm; capsules not twisted, (28–)30–70(–115) mm, wings 10–28(–34) mm wide.
→ 4
4. Leaves green or younger ones grayish green, moderately strigillose, rarely more densely strigillose, blades often lanceolate-elliptic to broadly elliptic, sometimes linear or lanceolate, 0.4–2.3(–3) cm wide; capsule wings (14–)18–28(–34) mm wide.
subsp. macrocarpa
4. Leaves gray, densely strigillose, blades very broadly elliptic to suborbiculate, rarely oblanceolate or elliptic, 2–4.3 cm wide; capsule wings 10–15(–24) mm wide.
subsp. incana
Source FNA vol. 10. FNA vol. 10.
Parent taxa Onagraceae > subfam. Onagroideae > tribe Onagreae > Oenothera > sect. Megapterium Onagraceae > subfam. Onagroideae > tribe Onagreae > Oenothera > sect. Gaura > subsect. Campogaura
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. linifolia, O. longissima, 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. suffulta, O. tetraptera, O. texensis, O. toumeyi, O. triangulata, O. triloba, O. tubicula, O. villosa, O. wolfii, O. xylocarpa
Subordinate taxa
O. macrocarpa subsp. fremontii, O. macrocarpa subsp. incana, O. macrocarpa subsp. macrocarpa, O. macrocarpa subsp. oklahomensis
Synonyms Megapterium macrocarpum, M. nuttallianum Gaura suffrutescens, G. bracteata, G. coccinea, G. coccinea var. arizonica, G. coccinea var. epilobioides, G. coccinea var. glabra, G. coccinea var. integerrima, G. coccinea var. parvifolia, G. epilobioides, G. glabra, G. induta, G. linearis, G. marginata, G. multicaulis, G. odorata, G. parvifolia, G. spicata
Name authority Nuttall: Cat. Pl. Upper Louisiana, no. 56. (1813) (Seringe) W. L. Wagner & Hoch: Syst. Bot. Monogr. 83: 214. (2007)
Web links