Flora of North America species comparison

Species 7 (7 in the flora).

Section Calylophus consists of 7 species (13 taxa) classified in two subsections distributed throughout the Great Plains to Arizona and south to central Mexico with a center of diversity in Texas (H. F. Towner 1977). P. H. Raven (1964) separated Calylophus from Oenothera as treated by P. A. Munz (1965) based on its peltate stigma and unusual sporogenous tissue (Towner). The peltate stigma can now be more properly interpreted as a variation from the typical Oenothera stigma, with the indusium enlarged and the lobes reduced (W. L. Wagner et al. 2007). Molecular studies (R. A. Levin et al. 2004) strongly support both the inclusion of Calylophus within Oenothera and the monophyly of the section by inclusion of a species from each of the subsections. Subsequent detailed analyses (B. Cooper, unpubl.) indicate that subsect. Salpingia is not monophyletic with subsect. Calylophus nested within it, indicating that subsections may not be justifiable as currently defined. All species, except O. serrulata, are self-incompatible and outcrossing; flowers diurnal to vespertine, opening in the early morning or from midafternoon to near sunset, wilting in one and one-half to two days; those species with diurnal flowers are pollinated by bees [especially Halictidae (halictids) and Anthophoridae (anthophorids), often oligolectic species], those with larger vespertine flowers are pollinated by hawkmoths (Towner). The self-compatible O. serrulata is autogamous and a PTH species. Recent work (M. Moore, pers. comm.) suggests that there is additional edaphic endemism within sect. Calylophus, which is being investigated using morphology and molecular analyses (B. Cooper, unpubl.), and will likely result in detection of previously unknown species in the section.

Meriolix Rafinesque ex Endlicher 1840 is a superfluous name that pertains here.

(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.)