White Flowers in South America: A New Species Ofantiphytum(echiochiloideae, Boraginaceae)

Abstract—Antiphytum charruasorum, a new endemic species from western Uruguay, is described. This is the only South American species in the genus with white corolla and an infra-medial cicatrix on the ventral face of the eremocarp, both features shared with the North American species ofAntiphytum, in sharp contrast with the blue corolla and the basal cicatrix at the end of a stipe-like prolongation that characterizes all South American species in the genus.Antiphytum charruasorumincreases the diversity of the genus in South America, as well as the endemism and distribution range into Uruguay. Moreover, this new species adds novel features inAntiphytumsuch as the irregularly dichasial inflorescences, the hirsute faucal appendages, the eremocarps with a tissue plug from the gynobase, and the habitat where the species has been reported.