Comparative leaf anatomy of Palicourea rigida and Palicourea coriacea (Rubiaceae) occurring in the municipality of Diorama, Goiás, Brazil

Abstract

This study aimed to perform a comparative anatomical study between Palicourea coriacea and Palicourea rigida (Rubiaceae), aiming to correlate possible anatomical changes to the variations of climatic factors found in the biome, and contribute to the taxonomic delimitation of the genus. The material was collected according to the usual recommendations in plant anatomy in an area of Cerrado sensu stricto, located in the municipality of Diorama – Goiás. We observed that the studied species share morphoanatomical diagnostic characteristics for the Rubiaceae family. However, some variations were found, such as styloid crystals, which were only found for species of the Psychotria genus, and which were considered a distinctive feature of the Psychotria genus. As styloid crystals were found in both P. coriacea and P. rigida, we suggest that it be used as a distinguishing feature of the tribe.