This distinctly large-flowered species (with petals ca. 2.5-5 cm long and elevated stigmas) is native to southeastern states, mostly from Miss. to N.C.. (Flowers open at night and fade after noon, as in biennis.) A pubescent cultigen derived from hybridization of grandiflora and the Californian species, O. elata Kunth, is known as O. glazioviana Micheli in Martius (= O. erythrocephala Borbas), which became cultivated (as "biennis") in Europe early after settlement, and then more widely distributed (Dietrich et al. 1997, Greiner 2008, Rostański & Verloove 2015; W). That robust cultigen differs from typical grandiflora in its more pubescent inflorescence, usually with some red-pustulate hairs (versus none), and its more reddish sepals. All records of grandiflora from Ky. may be based on glazioviana, but further review is needed. There is a coll. of grandiflora by C.W. Short (NY, PH) labeled "Lexington" (see also Short et al. 1833), and there have been reports from n. and w. Ky. (Linney 1882; Pr but none at MO). This species or O. glazioviana is currently known in some gardens of Lexington (FAYE), but naturalized plants are unknown.. In addition, BA reported O. elata Kunth. var. hirsutissima (S. Watson) W. Dietrich, which is a closely related western species, but that report was probably erroneous; no coll. has been located.