Taxonomic Revision of Senna ser. Spinescentes (Leguminosae, Cassieae), Including Two New South American Species

Alexandre Gibau de Lima; Marcelo Trovó; Roseli Lopes da Costa Bortoluzzi; Juliana Gastaldello Rando; Christine D. Bacon; Vidal de Freitas Mansano

doi:10.3417/2024877

Alexandre Gibau de Lima Jardim Botânico do Rio de Janeiro https://orcid.org/0000-0002-9168-2507
Marcelo Trovó Universidade Federal do Rio de Janeiro
Roseli Lopes da Costa Bortoluzzi Universidade do Estado de Santa Catarina
Juliana Gastaldello Rando Universidade Federal do Oeste da Bahia
Christine D. Bacon University of Gothenburg
Vidal de Freitas Mansano Instituto de Pesquisas do Jardim Botânico do Rio de Janeiro

DOI: https://doi.org/10.3417/2024877

Keywords: Amazonia, Andes, Bolivian flora, Brazilian flora, Caesalpinioideae, Cassia, endangered, endemic, riparian forests, Yungas

Abstract

Senna sect. Chamaefistula (DC. ex Collad.) H. S. Irwin & Barneby ser. Spinescentes H. S. Irwin & Barneby is restricted to the Neotropical region and has species distributed predominantly in the lowland forest of Amazonia. These species are morphologically distinguished by their scandent or viny habit, stipular thorns, and laterally compressed fruits with seeds parallel to fruit valves. Previous taxonomic treatments have recognized only two formally described species and one variety; nevertheless, they served as a baseline for a more comprehensive study. Based on the analysis of many specimens housed in herbaria and on fieldwork, we recognize five species belonging to Senna ser. Spinescentes including two newly described species, one from the Brazilian Amazon, S. manaosa A. Lima, Bortoluzzi & V. F. Mansano, and the other from the Bolivian Yungas, S. yungas A. Lima, Bortoluzzi & V. F. Mansano. We also recognize S. schultesiana (H. S. Irwin & Barneby) A. Lima & V. F. Mansano as a morphologically distinct species rather than a variety of S. spinescens (Hoffmanns. ex Vogel) H. S. Irwin & Barneby, and we propose a lectotypification for S. longiglandulosa (Benth.) H. S. Irwin & Barneby. We provide an identification key, morphological descriptions, taxonomic notes, illustrations, preliminary conservation assessments, and habitat and phenology data for each species of the series.

Author Biographies

Marcelo Trovó, Universidade Federal do Rio de Janeiro

Juliana Gastaldello Rando, Universidade Federal do Oeste da Bahia