Significant range extension of Streptanthus squamiformis (Brassicaceae), a Ouachita Mountain endemic

Abstract

Streptanthus squamiformis Goodman (Brassicaceae) is a plant narrowly endemic to the Athens Plateau; Central Hills, Ridges, and Valleys; and Central Mountain Ranges ecoregions of the Ouachita Mountains, and previously known from five adjacent counties in western Arkansas and southeastern Oklahoma. We document a 100-km range extension of this species to Perry County in central Arkansas, its first occurrence in the Fourche Mountains Ecoregion.