The varieties of Paepalanthus macrocaulon (Eriocaulaceae) from the Chapada Diamantina (Bahia, Brazil) circumscribed as two distinct species

Abstract

Paepalanthus macrocaulon (Eriocaulaceae) was described from the Botumirim region and adjacent areas in the Espinhaço Range, Minas Gerais, Brazil. In addition to the autonym, the species currently includes two accepted varieties described from the Pico das Almas, southern part of the Chapada Diamantina in Bahia (Brazil). Based on an extensive analysis of the type material, field populations, and herbarium specimens, we conclude that the two varieties from Bahia are distinct entities and should be recognized as two independent species, while P. macrocaulon is restricted to Minas Gerais. We propose two new status, one new name, and designate one lectotype. Detailed descriptions, illustrations, additional comments, and a comparative table are also provided. Paepalanthus kingii is easily distinguished from the type variety by the glabrous leaves with plain margin and the five series of glabrous involucral bracts with acuminate apex surpassing the floral disc. Paepalanthus raymondii may be differentiated from P. macrocaulon by the glabrous leaves with plain margin, pilose spathes and scapes, wider capitula, and the narrow spathulate floral bracts densely pilose abaxially. The two taxa treated here as species for the first time occur in sympatry and may be further differentiated by the scape pilosity and capitulum width, besides the shape and pilosity of both involucral and floral bracts.