(2922) Proposal to conserve the name Loasa rudis (“Nasa rudis”) against L. rhoeadifolia (Loasaceae)

Abstract

The genus Nasa was established by Weigend in 2006, encompassing species previously classified under Loasa. The distinction between the two genera is supported by the presence of a single bract per flower, a unique structure of the nectar scale, and molecular evidence. Among the widely collected and distributed taxa in Nasa is N. triphylla subsp. rudis, which spans from southern Mexico to Panama. Recent molecular evidence suggests elevating N. triphylla subsp. rudis to species rank, as it is morphologically and phylogenetically closer to N. dyeri than to the type subspecies of N. triphylla. N. rudis and N. dyeri exhibit distinct characteristics in comparison to N. triphylla, including robust basal stems, dark green calli at the base of petioles, and petals with long filiform appendages. N. rudis can be differentiated from N. dyeri by stem characteristics, stinging trichome cover, and pedicel length. The history of nomenclature for this taxon involves various names under Loasa, and the name "Loasa rhoeadifolia" is considered a synonym. Due to the lack of recognizable type material and the established usage of the name "Loasa rudis," it is recommended to conserve the name Loasa rudis for nomenclatural stability and to avoid further confusion.