Oenothera macrocarpa |
Oenothera triloba |
|||||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
bigfruit evening primrose, Missouri evening primrose, Ozark sundrop |
stemless evening-primrose |
|||||||||||||||||
Habit | Herbs caulescent, strigillose or glabrous, sometimes glandular puberulent distally; from a stout taproot, sometimes lateral roots producing adventitious shoots. | Herbs winter-annual, sometimes biennial, acaulescent or very short-caulescent, sparsely to moderately strigillose and glandular puberulent, sometimes one hair type predominant, rarely glabrate, sometimes also very sparsely hirsute, especially on leaf veins; from a slender or, sometimes, stout taproot. | ||||||||||||||||
Stems | moderately leafy, (1–)4–40(–60) cm. |
(when present) ascending, 1–several, densely leafy, 0–20 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, sometimes also cauline, (2.5–)6–25(–32) × (0.6–)1.5–4(–5) cm, thin; petiole (0.5–)1–8 cm; blade oblanceolate to elliptic, margins irregularly pinnatifid, sometimes subentire, apex acute to obtuse or rounded. |
||||||||||||||||
Flowers | usually 1 or 2, rarely more, opening per day near sunset, fading next morning, sometimes (subspp. |
1–4 opening per day near sunset, without noticeable scent; buds with subequal free tips 2–7 mm; floral tube (20–)28–95(–138) mm; sepals (6–)10–30(–35) mm; petals pale yellow, fading pale orange, drying lavender, (10–)12–30(–38) mm; filaments (5–)8–15(–18) mm, anthers (3.5–)4–11 mm; style (3.4–)4.2–11.5(–16.3) mm, stigma usually surrounded by anthers, sometimes (especially in some Texas populations) exserted beyond anthers. |
||||||||||||||||
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. |
woody in age, rhombic-obovoid, winged, wings broadly triangular, 5–10 mm wide, often terminating in a hooked tooth, (10–)15–25(–28) × 4–8 mm (excluding wings), valve surface reticulate, dehiscent 1/8–1/3 their length. |
||||||||||||||||
Seeds | numerous, rarely as few as 8, in 1 row per locule, obovoid, (2–)3–5 × 1–2.3 mm. |
asymmetrically cuneiform, (2.1–)2.5–3(–3.3) 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. |
|||||||||||||||||
Oenothera macrocarpa |
Oenothera triloba |
|||||||||||||||||
Phenology | Flowering (Feb–)Mar–May(–Jul). | |||||||||||||||||
Habitat | Scattered to common in clay, sandy or rocky soil, playas, floodplains, creek beds, slopes and flats, moist sites, disturbed sites, roadsides, old fields, in Larrea deserts, prairies, glades. | |||||||||||||||||
Elevation | 300–1900 m. (1000–6200 ft.) | |||||||||||||||||
Distribution |
c United States; n Mexico; s United States
|
AL; AR; CO; DC; IL; IN; KS; KY; MD; MO; NM; OH; OK; PA; TN; TX; VA; Mexico (Baja California, Chihuahua, Nuevo León)
|
||||||||||||||||
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.) |
Oenotheratriloba is primarily a species of the high plains from eastern Socorro County, New Mexico, east through all but eastern Texas, Oklahoma, to southern Kansas, east of Meade and Pawnee counties and south of Douglas and Saline counties. It becomes more sporadic eastward into Missouri south of the Missouri River, northwestern and north-central Arkansas, central and eastern Tennessee, northern Alabama, and Logan and Warren counties, Kentucky; also known from disjunct sites in northern Mexico from Nuevo León, Chihuahua, and Baja California, Mexico; and, introduced in Illinois, Indiana, Ohio, Kentucky (Campbell and Fayette counties), Pennsylvania, Virginia, Maryland, and the District of Columbia. Areas where it was introduced are represented by old collections; no current information indicates their continued presence in any of these areas. It was recently collected in Baca County, Colorado. Capsules of dead plants sometimes form pineconelike clusters of ten to 100 or more capsules. The illegitimate names Lavauxia nuttalliana Spach and L. triloba (Nuttall) Spach var. watsonii Britton pertain here. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
||||||||||||||||
Key |
|
|||||||||||||||||
Source | FNA vol. 10. | FNA vol. 10. | ||||||||||||||||
Parent taxa | Onagraceae > subfam. Onagroideae > tribe Onagreae > Oenothera > sect. Megapterium | Onagraceae > subfam. Onagroideae > tribe Onagreae > Oenothera > sect. Lavauxia > subsect. Lavauxia | ||||||||||||||||
Sibling taxa | ||||||||||||||||||
Subordinate taxa | ||||||||||||||||||
Synonyms | Megapterium macrocarpum, M. nuttallianum | Lavauxiahamata wooton, L. triloba, L. watsonii, O. hamata, O. rhizocarpa, O. roemeriana, O. triloba var. parviflora, O. triloba | ||||||||||||||||
Name authority | Nuttall: Cat. Pl. Upper Louisiana, no. 56. (1813) | Nuttall: J. Acad. Nat. Sci. Philadelphia 2: 118. (1821) | ||||||||||||||||
Web links |