Species of Croton L. sect. Cyclostigma Griseb. and Croton L. sect. Luntia (Raf.) G. L. Webster subsect. Matourenses G. L. Webster (Euphorbiaceae s.s.) occuring within Brazilian Amazon

Abstract

As part of a taxonomic revision of Brazilian Amazonia species of Croton L., the following species of Croton sect. Cyclostigma Griseb. and Croton sect. Luntia (Raf.) G. L. Webster subsect. Matourenses G. L. Webster were studied: Croton urucurana Baill., C. draconoides Müll. Arg., C. trombetensis R. Secco, P. E. Berry & N.A. Rosa, C. sampatik Müll. Arg., C. palanostigma Kl., C. pullei Lanj. and C. matourensis Aubl. This study was based on field work in the States of Pará and Maranhão, and material deposited in herbaria IAN, INPA, MG e RB, including the types. Some of the species, such as C. urucurana, C. draconoides, C. palanostigma, and C. sampatik, are frequently found with misidentification in herbaria. The taxonomic position of the species within sections and their affinities are discussed, and a dychotomic key and illustrations were elaborated for a better understanding of the taxa.