Oenothera mckelveyae |
Oenothera riparia |
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Mckelvey's beeblossom |
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Habit | Herbs perennial, clumped, long-villous, more sparsely so distally, hairs erect, 2–4 mm, also strigillose, sometimes glabrate distally or also sparsely glandular puberulent; from twisted, woody rootstock. | Herbs perennial, sparsely strigillose, becoming glabrate distally, usually also glandular puberulent distally; from a somewhat fleshy rootstock, forming adventitious roots where submerged. |
Stems | ascending, branched below or just above ground, branched also proximal to inflorescences, 30–70(–120) cm. |
erect or ascending, usually many-branched throughout, proximal branches often somewhat spongy, 50–120 cm. |
Leaves | in a basal rosette and cauline, basal 3–17 × 0.8–2 cm, blade oblanceolate, cauline 1–6.5 × 0.1–1.5 cm, sessile, blade narrowly oblanceolate to elliptic, margins conspicuously sinuate-dentate, often undulate. |
in a basal rosette and cauline, softly succulent, 4–13.5 × 0.8–2.1 cm, petiole 0–1.5 cm, blade lanceolate to elliptic-lanceolate, margins remotely denticulate. |
Inflorescences | slender. |
erect, flowers in axils of distalmost few nodes. |
Flowers | 4-merous, zygomorphic, opening near sunset; floral tube 2–3.5 mm; sepals 6–12 mm; petals white, fading dark pink to red, slightly unequal, elliptic-obovate, 7–11 mm, long-clawed; stamens presented in lower 1/2 of flower, filaments 5–9 mm, lanate at very base, anthers 2–4 mm, pollen 90–100% fertile; style 9–16 mm, stigma exserted beyond anthers at anthesis. |
opening near sunrise; buds with free tips 0.5–2(–5) mm, erect to spreading; floral tube 14–20 mm; sepals 20–30 mm; petals bright yellow, fading pale pink or lavender, 16–27 mm; filaments 10–15 mm, anthers 7–8 mm, pollen 85–100% fertile; style 15–30 mm, stigma exserted beyond anthers at anthesis. |
Capsules | reflexed, lanceoloid to narrowly ovoid, narrowly 4-winged, 8–19 × 1.5–2 mm, tapering to a sterile stipe 3–9 mm. |
oblong-clavate to oblong-ellipsoid, 4-angled or 4-winged, and wings 0.1–0.2 mm, 7–15 × 4–6 mm, stipe 2–5 mm; sessile. |
Seeds | (1 or)2–4, 2–3 × 1 mm, yellowish to reddish brown. |
0.8 × 0.4 mm. |
2n | = 14. |
= 56. |
Oenothera mckelveyae |
Oenothera riparia |
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Phenology | Flowering Mar–Jun. | Flowering May–Jul. |
Habitat | Sandy soil. | Isolated colonies in or at edge of water in marshes or slow-running rivers, apparently with at least some tidal influence. |
Elevation | 0–300 m. (0–1000 ft.) | 0–10 m. (0–0 ft.) |
Distribution |
TX; Mexico (Nuevo León, Tamaulipas) |
GA; NC; SC; VA |
Discussion | Oenothera mckelveyae, on the Rio Grande Plain, is found in an area bounded by from Dimmit and LaSalle counties east to Karnes and Refugio counties in the north, southward through south Texas, extending to northeastern Tamaulipas and adjacent Nuevo León. P. H. Raven and D. P. Gregory (1972[1973]) found Oenothera mckelveyae to be self-incompatible. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Oenothera riparia has not been accepted as a distinct species for a long time. The conservative approach used by G. B. Straley (1977) is here followed in recognizing a broadly delimited O. fruticosa, except that the very distinctive coastal tidal-freshwater semi-aquatic octoploid populations (Straley 1982) are recognized as O. riparia. Plants of these coastal populations, which occur from southern Virginia to North Carolina, are more robust, more branched, and less pubescent than those of the two subspecies of O. fruticosa, and have slightly succulent leaves and more prominent adventitious roots (Straley 1982; D. Boufford, pers. comm.). Further field studies and cytological analyses are needed to fully understand the geographical and ecological limits of O. riparia and confirm that it is strictly an octoploid species. K. N. Krakos et al. (2014) determined that Oenothera riparia is self-incompatible and is pollinated by bees (Bombus, Lassioglossum, Megachile, Parallelia, Xylocopa, and Zale). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 10. | FNA vol. 10. |
Parent taxa | ||
Sibling taxa | ||
Synonyms | Gaura villosa var. mckelveyae, Gaura mckelveyae | Kneiffia riparia, O. tetragona var. riparia |
Name authority | (Munz) W. L. Wagner & Hoch: Syst. Bot. Monogr. 83: 213. (2007) | Nuttall: Gen. N. Amer. Pl. 1: 247. (1818) |
Web links |