Oenothera linifolia |
Oenothera brachycarpa |
|
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threadleaf evening-primrose, threadleaf sundrop |
shortfruit evening-primrose |
|
Habit | Herbs annual, caulescent, strigillose or glabrous, also often glandular puberulent, especially distally; from a sparsely branched taproot. | Herbs acaulescent or sometimes caulescent, strigillose, also hirsute, hairs often with reddish purple pustulate base, glandular puberulent distally; from a woody taproot, sometimes lateral roots producing adventitious shoots. |
Stems | unbranched or with many ascending branches arising near base, erect, 10–50 cm. |
(when present) ascending, longer ones becoming decumbent, usually densely leafy, 0–20(–36) 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, sometimes also cauline, (3.1–)5–21(–34) × (0.3–)1.5–3.5(–5.3) cm; petiole (0.8–)2.5–11(–15) cm; blade usually lanceolate to elliptic, rhombic-obovate, sometimes suborbicular or linear, usually irregularly pinnatifid, some sinuses extending nearly to midrib, usually with a large terminal lobe (0.1–)1.5–2(–2.4) cm, margins erose, apex acute to obtuse or rounded. |
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. |
usually 1–3, rarely more, opening per day near sunset, weakly scented; buds with unequal free tips 1–7 mm; floral tube (90–)120–210(–220) mm; sepals 38–55 mm; petals pale yellow to yellow, fading pale orange to pink, drying lavender to purple, usually broadly rhombic-obovate, sometimes obovate, (38–)45–58(–62) mm, distal margin usually erose; filaments (16–)20–32 mm, anthers (8–)13–21 mm; style (123–)155–240(–255) mm, stigma exserted beyond anthers at anthesis. |
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. |
leathery or corky, ovoid to narrowly ellipsoid, ± winged, wings 0–3(–5) mm wide, sometimes capsule with corky thickening between wings, then capsule only 4-angled, body (12–)18–40 × 6–10 mm, dehiscent 1/4 their length; pedicel 0–3 mm. |
Seeds | clustered in each locule, ovoid, surface minutely papillose, 1 × 0.5 mm. |
usually numerous, in 1 or 2 rows per locule, obovoid to subcuboid, 3–5 × 1.8–2.2 mm. |
2n | = 14. |
= 14. |
Oenothera linifolia |
Oenothera brachycarpa |
|
Phenology | Flowering Apr–Jun(–Aug). | Flowering Mar–Aug. |
Habitat | Prairies, open woodlands, open rocky and sandy sites, roadsides. | Rocky sites, usually on limestone, shale, or gypsum, on igneous substrates from canyons and slopes in Chihuahuan Desert scrub, grasslands, oak-pine-juniper woodlands, open sites in ponderosa pine-Douglas fir forests. |
Elevation | 0–400 m. (0–1300 ft.) | 1000–2700 m. (3300–8900 ft.) |
Distribution |
AL; AR; FL; GA; IL; KS; KY; LA; MO; MS; NC; OK; SC; TN; TX
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AZ; NM; TX; Mexico (Chihuahua, Coahuila, Durango, Sonora)
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Discussion | Kneiffia linearifolia Spach (1835) is an illegitimate name based on Oenothera linifolia. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Oenotherabrachycarpa occurs from southeastern Arizona in southern Navajo, southeastern Pima, Graham, Santa Cruz, and Cochise counties, east across southern New Mexico to Val Verde and Pecos counties in trans-Pecos Texas. (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. Megapterium |
Sibling taxa | ||
Synonyms | Kneiffia linifolia, O. linifolia var. glandulosa, Peniophyllum linifolium | Lavauxia brachycarpa, L. graminifolia, L. wrightii, Megapterium brachycarpum, M. brachycarpum var. wrightii, O. australis, O. brachycarpa var. wrightii, O. cespitosa subsp. australis, O. cespitosa var. australis, O. graminifolia, O. wrightii, Pachylophus australis |
Name authority | Nuttall: J. Acad. Nat. Sci. Philadelphia 2: 120. (1821) | A. Gray: Smithsonian Contr. Knowl. 3(5): 70. (1852) |
Web links |