Palicourea Aubl. (Rubiaceae) da Mata Atlântica brasileira

Abstract

PalicoureaAubl. (Rubiaceae) is a neotropical genus with ca. 250 species in the world, of which 56 species, 6 subspecies, and 1 variety arefound in Brazil. They are popularly known as “erva-de-rato”. Brazilian species occur mainly in the understory of the Atlantic Forest, the Amazon Forest, and fewer in the Cerrado and occasionally in Campo rupestre.ThePalicourea species can be recognized by the presence of bilobed stipules, colored inflorescences, tubular flowers, presence of nectariferous disk and a ring of trichomes in the inner region of the corolla.The taxa circumscription at a specific level becomes very complex, onsidering intraspecific morphological diversity and overlapping characters.This study aimed to review the taxonomy of Palicoureaspecies of Brazilian Atlantic Forest, providing updated descriptions and inferences about the outlines of the species by analysis of morphological and molecular phylogeny, using markersITS, ETS and trnL/F.The results revealed the existence of 11 species of Palicourea for the Brazilian Atlantic Forest: P. blanchetiana Schltdl., P. crocea (Sw.) Roem. & Schult., P. fulgens (Müll. Arg.) Standl., P. guianensis Aubl., P. longepedunculata Gardner, P. macrobotrys (Ruiz & Pav.) Schult., P. marcgravii A.St.-Hil., P. rigida Kunth, P. rudgeoides (Müll. Arg.) Standl., P. tetraphylla Cham. & Schltdl. and P. veterinariorum J.H.Kirkbr. An identification key and the descriptions, data distribution, etymology, popular name, conservation status, time of flowering and fruiting, comments, list of materials examined and illustrationsare provided for all recognized species. Two new lectotypification sand three new synonyms were establishedand two species and one subspecies were excluded.The species segregation was only possible when the morphological features were evaluated in together, clusteringthe type and form of the inflorescence with flower color patterns, the lobes shape of stipules, the nectariferous disk type and variations in section transversal of the stems.Theanalysis of morphological phylogeny corroborated the complexityof Palicourea, revealing low indexes of morphological proximity, with internal resolution of bootstrap between 14 and 56%, and the ineffectivenessof ITS, ETS and trnL/F markers for molecular analysis. The DNA amplification protocol for studied species was not possible, preventing the sequencing of the samples and, consequently, the possibility to infer the phylogeny based on molecular data of the Palicourea studied.