Fabaceae Lindl. in a Conservation Unit in the Semi-Arid Region of Paraíba, Brazil Author Gomes, Aureliana Santos Departamento de Geografia - Universidade Federal de Campina Grande: - Campus I, Centro de Humanidades. Unidade Acadêmica de Geografia-UAG, R. Aprígio Veloso, 882, Universitário, Campina Grande, PB, 58428 - 830, Brasil. Author Rodrigues, Erimágna De Morais Author Moura, Débora Coelho Departamento de Geografia - Universidade Federal de Campina Grande: - Campus I, Centro de Humanidades. Unidade Acadêmica de Geografia-UAG, R. Aprígio Veloso, 882, Universitário, Campina Grande, PB, 58428 - 830, Brasil. Author Melo, José Iranildo Miranda De Programa de Pós-Graduação em Ecologia e Conservação - Universidade Estadual da Paraíba - UEPB, Departamento de Biologia, Centro de Ciências Biológicas e da Saúde, Av. das Baraúnas 351, Campus Universitário, Bairro Universitário, Campina Grande, PB, 58429 - 500, Brasil. Author Ribeiro, Rayane De Tasso Moreira Universidade Federal Rural de Pernambuco, Departamento de Biologia, Laboratório de Taxonomia Vegetal (LATAX), Rua Dom Manoel de Medeiros, s / n, Campus Dois Irmãos, 52.171 - 900, Recife, PE, Brasil. Author Queiroz, Rubens Teixeira De Departamento de Sistemática e Ecologia- Universidade Federal da Paraíba - Campus I, Centro de Ciências Exatas e da Natureza, Jardim Universitário, Castelo Branco, João Pessoa, PB, 58051 - 900, Brasil. & Author for correspondence: rbotânico @ gmail. com text Phytotaxa 2022 2022-07-19 555 1 17 41 http://dx.doi.org/10.11646/phytotaxa.555.1.2 journal article 102841 10.11646/phytotaxa.555.1.2 2e2412c5-4709-4f24-b489-db901a316721 1179-3163 6875635 17. Lachesiodendron viridiflorum ( Kunth 1821: 81–83 ) P.G. Ribeiro, L.P. Queiroz & Luckow (2018: 45–51) Trees , branches glabrous, spines. Nectary petiolar, sessile. Stipules caducous. Leaves bipinnate, 14–16–foliolate, leaflets opposite, oblong, venation actinodromous, translucid punctuation absent. Inflorescence spikes, axillary. Flowers sessile, actinomorphic, diplostemonous; calyx gamosepalous, sepals 5, corolla gamopetalous, tubular, green, petals 5; androecium dialystaminous, homodinamous, anthers longitudinal; ovary superior, sessile, pluriovulate. Fruit legume, sessile, linear, plane-corrugate, margin straight, epicarp glabrous, brown. Seeds obovate, plane, coat brown, hilum basal. Examined material:— BRAZIL . Paraíba : Maturéia , Pico do Jabre , 950 m elev,. 04 November 2019 , fl., Aureliana Gomes 472 ( JPB ) . Distribution and ecology:— The species occurs in Argentina , Bolivia , Colombia , Ecuador , Guatemala , Mexico , Peru and Venezuela and in Brazil , where it is registered in the Central-West (MS), Northeast (AL, BA, CE, PB, PE, PI, RN, SE) and Southeast (MG), associated with the Caatinga and Cerrado domains in areas of seasonal deciduous forest (Freire Júnior & Silva 2019; Flora do Brasil 2020 ). Phenology:— Registered with flowers in November. Taxonomic discussion:— Lachesiodendron viridiflorum can be recognized, mainly, by the armed branches with thorns, inflorescence in spikes, green flowers and sessile legume. Among the species of the Mimosoideae clade found in the area, this species was the only with thorns, while all other species of the clade are armed and aculeate.