Oenothera sect. Gauropsis
decumbent to ascending, branched.
cauline (basal rosette not observed), (0.3–)0.6–1.5(–2.5) cm;
blade margins sinuate-denticulate to subentire.
solitary flowers in axils of distal leaves.
opening near sunset, with a sweet scent or nearly unscented;
buds erect, terete, without free tips or free tips minute;
floral tube (8–)10–15(–17) mm;
sepals usually splitting along one suture, remaining coherent and reflexed as a unit at anthesis, rarely separating in pairs;
petals usually pink, rarely white, streaked or flecked with red, fading bright purple, obovate;
stigma deeply divided into 4 linear lobes.
woody, ovoid, narrowly winged, abruptly constricted to a conspicuous, sterile beak, indehiscent;
sessile.
numerous, in 2–4 irregular rows per locule, asymmetrically cuneiform or oblanceoloid and weakly angled (probably resulting from compression from adjacent seeds during development), surface glossy, obscurely reticulate, appearing finely granular.
= 14.
Oenothera sect. Gauropsis
Species 1.
Section Gauropsis consists of one distinctive species with pink petals, flecked with red, and ovoid, indehiscent, narrowly winged capsules and an apex abruptly constricted to a conspicuous sterile beak. It is self-compatible with flowers vespertine, outcrossing, and pollinated by noctuid moths and occasionally hawkmoths, such as Hyles lineata (W. L. Wagner 1984). Wagner indicated that O. canescens forms adventitious shoots from lateral roots, but this feature should be re-examined, since the closely related O. speciosa (sect. Hartmannia) reproduces by rhizomes.
One illegitimate later homonym has been published for this taxon: Gauropsis (Torrey & Frémont) Cockerell (1900) not C. Presl (1851).
(Discussion copyrighted by Flora of North America; reprinted with permission.)
