Oenothera linifolia |
Oenothera mexicana |
|
---|---|---|
threadleaf evening-primrose, threadleaf sundrop |
Mexican evening primrose |
|
Habit | Herbs annual, caulescent, strigillose or glabrous, also often glandular puberulent, especially distally; from a sparsely branched taproot. | Herbs annual, moderately to sparsely strigillose and densely long-villous, sometimes also becoming glandular puberulent distally. |
Stems | unbranched or with many ascending branches arising near base, erect, 10–50 cm. |
erect to ascending, usually unbranched, or with arcuate lateral branches arising from rosette, 15–40(–60) 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 6–10 × 1–2.5 cm, cauline 3–7.5 × 0.8–2 cm; blade usually grayish green, narrowly oblanceolate to narrowly oblanceolate, margins deeply lobed, lobes usually dentate; bracts distalmost erect, revolute. |
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 opening per day near sunset; buds erect, with free tips erect or appressed, 0.5–2.5 mm; floral tube 23–28 mm; sepals 5–12 mm; petals yellow, fading orange, broadly obovate or shallowly obcordate, 6–15 mm; filaments 4–12 mm, anthers 3–4 mm, pollen 85–100% fertile; style 27–40 mm, stigma surrounded by 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. |
cylindrical, sometimes slightly enlarged toward apex, 25–45 × 2.5–3 mm. |
Seeds | clustered in each locule, ovoid, surface minutely papillose, 1 × 0.5 mm. |
ellipsoid to subglobose, 0.8–1.2 × 0.3–0.5 mm. |
2n | = 14. |
= 14. |
Oenothera linifolia |
Oenothera mexicana |
|
Phenology | Flowering Apr–Jun(–Aug). | Flowering Apr–May. |
Habitat | Prairies, open woodlands, open rocky and sandy sites, roadsides. | Open, sandy sites. |
Elevation | 0–400 m. (0–1300 ft.) | 30–200 m. (100–700 ft.) |
Distribution |
AL; AR; FL; GA; IL; KS; KY; LA; MO; MS; NC; OK; SC; TN; TX
|
TX |
Discussion | Kneiffia linearifolia Spach (1835) is an illegitimate name based on Oenothera linifolia. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Oenothera mexicana is known only from southeastern Texas (Atascosa, Aransas, Bexar, Brooks, Burleson, De Witt, Frio, Gonzales, Kenedy, Medina, Newton, Refugio, San Patricio, Waller, and Washington counties). It is self-compatible and autogamous, but not a PTH species. (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. Oenothera > subsect. Raimannia |
Sibling taxa | ||
Synonyms | Kneiffia linifolia, O. linifolia var. glandulosa, Peniophyllum linifolium | O. laciniata var. mexicana, O. sinuata var. hirsuta, Raimannia mexicana |
Name authority | Nuttall: J. Acad. Nat. Sci. Philadelphia 2: 120. (1821) | Spach: Nouv. Ann. Mus. Hist. Nat. 4: 347. (1836) |
Web links |