Pectocarya anisocarpa, a new species of Boraginaceae, and a revised key for the genus in western North America

Abstract

Pectocarya is a genus of 13 currently accepted taxa in Boraginaceae, subtribe Cryptanthinae. The genus has an amphitropical distribution in the New World, with eight taxa in western North America, seven in South America, and two occurring in both continents. Members of Pectocarya are distinctive in having a bilaterally or radially symmetrical fruit of four strongly divergent nutlets. Taxa within the genus are distinguished largely by the morphology of the nutlets, including shape, size, margin, posture, and variability both within a fruit and/or within a plant. Pectocarya ‘‘anisocarpa’’ (Boraginaceae) was previously named and described, but not validly published. Along with taxon-specific nutlet ornamentation, P. ‘‘anisocarpa’’ has fruits within a plant that are monomorphic and nutlets within a fruit that are heteromorphic. It is common throughout its range, which in the United States includes the southern half of California, Arizona, and southern Utah to the east. The species’ southernmost extent is in northwestern Baja California, Mexico. It is often encountered in mixed populations with congeners, and has been confused historically with P. penicillata and P. linearis var. ferocula in California and Baja California and P. heterocarpa in Arizona and Utah. Here we validly publish the name P. anisocarpa, as well as provide illustrations, an image of the holotype specimen, and a range map of the new taxon. A revised taxonomic key and photographs of the fruits of the North American Pectocarya taxa are also included.