Oenothera linifolia |
Oenothera arida |
|
---|---|---|
threadleaf evening-primrose, threadleaf sundrop |
trans-Pecos beeblossom |
|
Habit | Herbs annual, caulescent, strigillose or glabrous, also often glandular puberulent, especially distally; from a sparsely branched taproot. | Herbs perennial, clumped, strigillose and glandular puberulent throughout, also sparsely villous; from stout roots. |
Stems | unbranched or with many ascending branches arising near base, erect, 10–50 cm. |
erect, usually branched several cm belowground or from near base, sometimes also branched distally, 20–60(–100) 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, basal 2–4 × 0.4–0.8 cm, petiole0–0.4 cm, blade narrowly oblanceolate to narrowly spatulate; cauline 0.5–5 × 0.1–0.8 cm, petiole 0–0.3 cm, blade narrowly lanceolate or very narrowly elliptic, margins subentire or sinuate-denticulate. |
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. |
4-merous, nearly actinomorphic, opening near sunset; floral tube 9–13 mm; sepals 7–9 mm; petals white, fading pink to pale red, slightly unequal, rhombic, 7–8 mm, short-clawed; filaments 3–4 mm, anthers 4–5 mm, pollen 85–100% fertile; style 18–22 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. |
erect, fusiform, often slightly curved, weakly 4-angled, (9–)13–17 × 2–3 mm, valves with inconspicuous raised midrib; sessile. |
Seeds | clustered in each locule, ovoid, surface minutely papillose, 1 × 0.5 mm. |
(1–)3 or 4, yellowish or light brown, 2–3.5 × 1–2 mm. |
2n | = 14. |
= 14. |
Oenothera linifolia |
Oenothera arida |
|
Phenology | Flowering Apr–Jun(–Aug). | Flowering Apr–Aug. |
Habitat | Prairies, open woodlands, open rocky and sandy sites, roadsides. | Sandy flats and washes. |
Elevation | 0–400 m. (0–1300 ft.) | 1300–1800 m. (4300–5900 ft.) |
Distribution |
AL; AR; FL; GA; IL; KS; KY; LA; MO; MS; NC; OK; SC; TN; TX
|
TX; Mexico (Chihuahua) |
Discussion | Kneiffia linearifolia Spach (1835) is an illegitimate name based on Oenothera linifolia. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Oenothera arida is known only from several areas in the foothills of the Davis Mountains in eastern Jeff Davis County, northeastern Presidio County, and northern Brewster County, and from areas near Gallego and Chihuahua in Chihuahua, Mexico. P. H. Raven and D. P. Gregory (1972[1973]) determined O. arida to be self-incompatible. (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. Xerogaura |
Sibling taxa | ||
Synonyms | Kneiffia linifolia, O. linifolia var. glandulosa, Peniophyllum linifolium | Gaura macrocarpa |
Name authority | Nuttall: J. Acad. Nat. Sci. Philadelphia 2: 120. (1821) | W. L. Wagner & Hoch: Syst. Bot. Monogr. 83: 211. (2007) |
Web links |