Oenothera sect. Leucocoryne
Onagraceae subfam. onagroideae
several(–many), decumbent to ascending, usually branched.
in a basal rosette and cauline, cauline 1.8–7 cm;
blade margins weakly serrulate to subentire, sinuate-pinnatifid, or coarsely sinuate-dentate.
stipules present or absent.
solitary flowers in axils of distal leaves.
opening near sunset, scent unknown or unscented;
buds erect, terete, with free tips;
floral tube 5–30 mm;
sepals usually splitting along one suture, remaining coherent and reflexed as a unit at anthesis, rarely separating in pairs;
petals white, fading lavender to pink [or deep purple], obovate to obcordate;
stigma deeply divided into 4 linear lobes.
floral tube present or, rarely, absent;
sepals 2 or 4 (very rarely 3), deciduous with floral tube, petals, and stamens;
petals yellow, white, pink, red, rarely in combination.
hard and leathery, straight, clavate or obovoid, winged, wings 0.5–4 mm, apex rounded, obtuse or bluntly acuminate, proximal part a sterile pedicel-like base (stipe), gradually tapering to base, valve midrib raised, dehiscent at apex or nearly throughout body;
sessile.
numerous, clustered in each locule, narrowly obovoid, surface glossy, appearing granular, but minutely papillose under magnification.
= 14.
Oenothera sect. Leucocoryne
Onagraceae subfam. onagroideae
Species 5 (2 in the flora).
Section Leucocoryne consists of five species that occur from southern Texas, through northern Mexico to the Trans-Volcanic Belt of central Mexico, southward to Guatemala, Nicaragua, and Costa Rica, in openings in pine-oak or conifer forests on slopes or along streams (or arroyos), sometimes along roadsides or other weedy habitats, at 1400–2800(–3250) m elevation.
Species of section Leucocoryne share white petals, have similar capsule shape with a rounded to bluntly acuminate apex, and buds with free tips. All but Oenothera dissecta A. Gray ex S. Watson were formerly included in a more broadly defined sect. Hartmannia. Oenothera dissecta, previously included in sect. Gauropsis (P. A. Munz 1965; W. L. Wagner 1984), was transferred to sect. Leucocoryne, because it has capsules most similar to those of other white-flowered species grouped here (Wagner et al. 2007). All sect. Leucocoryne species are self-compatible (unknown in O. luciae-julianiae W. L. Wagner), the flowers vespertine, pollinated by hawkmoths or autogamous (O. kunthiana and presumably O. luciae-julianiae). Oenothera kunthiana is a PTH species and forms a ring of 14 chromosomes in meiosis; O. luciae-julianiae also appears to be a PTH species, indicated by lowered pollen fertility (Wagner 2004). Section Leucocoryne species are diploid (n = 7), except O. dissecta, which is known exclusively as a tetraploid (n = 14); the chromosomes of O. luciae-julianiae have not been examined.
Oenothera dissecta and O. luciae-julianiae both occur in Mexico. Oenothera dissecta occurs in flats in Durango, Jalisco, San Luis Potosí, and Zacatecas; O. luciae-julianiae occurs in pine-oak forest habitats in the Sierra Madre Occidental from Chihuahua south through Durango, Guanajuato, Nayarit, Jalisco, Michoacán, and Querétaro.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Genera 21, species 582 (16 genera, 246 species in the flora).
Onagroideae encompass the main lineage of the family, after the early branching of Ludwigia (R. A. Levin et al. 2003, 2004). This large and diverse lineage is distinguished by the presence of a floral tube beyond the apex of the ovary; sepals deciduous with the floral tube, petals, and stamens; pollen shed in monads (or tetrads in Chylismia sect. Lignothera and all but one species of Epilobium); ovular vascular system exclusively transseptal (R. H. Eyde 1981); ovule archesporium multicellular (H. Tobe and P. H. Raven 1996); and change in base chromosome number from x = 8 in Ludwigia to x = 10 or x = 11 at the base of Onagroideae (Raven 1979; Levin et al. 2003). Molecular work (Levin et al. 2003, 2004) substantially supports the traditional tribal classification (P. A. Munz 1965; Raven 1979, 1988); tribes are recognized to delimit major branches within the phylogeny of Onagroideae, where the branches comprise strongly supported monophyletic groups of one or more genera.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
1. Petals 20–43 mm; pollen 85–100% fertile; stigmas exserted beyond anthers at anthesis; floral tubes 10–30 mm. | O. tetraptera |
1. Petals 8–25 mm; pollen 35–65% fertile; stigmas surrounded by anthers at anthesis; floral tubes 5–31 mm. | O. kunthiana |
WildflowerSearch
iNaturalist
