New taxonomic circumscription to Chamaecrista ser. Setosae (H. S. Irwin & Barneby) H. S. Irwin & Barneby (Leguminosae, Caesalpinioideae) Author Oliveira, Jaqueline Aparecida De 0000-0002-6191-8021 Universidade Federal de Goiás, Departamento de Botânica, CP 131, 740001 - 970, Goiânia, GO, Brasil & jaquelinebiooliveira @ gmail. com; https: // orcid. org / 0000 - 0002 - 6191 - 8021 jaquelinebiooliveira@gmail.com Author Mendes, Thainara Policarpo 0000-0002-5349-0045 Universidade Estadual Paulista ‘‘ Júlio de Mesquita Filho’ ’, Campus Botucatu, Departamento de Botânica, Instituto de Biociências, CP 510 ,, SP 18618 - 970, Brazil & thainara. bio. ufg @ gmail. com; https: // orcid. org / 0000 - 0002 - 5349 - 0045 thainara.bio.ufg@gmail.com Author Souza, Alessandro Oliveira De 0000-0002-6191-8021 jaquelinebiooliveira @ gmail. com; https: // orcid. org / 0000 - 0002 - 6191 - 8021 & alessandro 341 @ hotmail. com; https: // orcid. org / 0000 - 0002 - 7057 - 3942 jaquelinebiooliveira@gmail.com Author Silva, Marcos José Da 0000-0001-9717-5701 Universidade Federal de Goiás, Laboratório de Morfologia e Taxonomia Vegetal, Departamento de Botânica, Instituto de Ciências Biológicas, CP 131, Goiânia, GO 74001 - 970, Brazil & marcos _ agrorural @ hotmail. com; https: // orcid. org / 0000 - 0001 - 9717 - 5701 marcos_agrorural@hotmail.com text Phytotaxa 2021 2021-03-12 490 2 118 158 http://dx.doi.org/10.11646/phytotaxa.490.2.1 journal article 10.11646/phytotaxa.490.2.1 1179-3163 5753717 Chamaecrista exsudans (Benth.) H.S. Irwin & Barneby, Mem. New York Bot. Gard. 35: 650. 1982 . Cassia exsudans Benth., J. Bot. (Hooker) 2(4): 80. 1840 . Type :— BRAZIL : Minas Gerais : Ouro Preto , Cachoeira (“Caxoeira”) do Campo, 1839, (fl), Claussen 25 ( lectotype : K-00055549, designated by Bentham in Martius (1870), isolectotype: P- 00836007). = Chamaecrista xanthadena (Mart. ex Benth.) H.S. Irwin & Barneby, Mem. New York Bot. Gard. 35: 650. 1982 . Cassia exsudans var. xanthadena Mart. ex Benth. in Mart., Fl. Bras. 15: 152. 1870 . Cassia xanthadena (Mart. ex Benth.) H.S. Irwin & Barneby, Mem. New York Bot. Gard. 30: 58. 1978 . Type:— BRAZIL : Minas Gerais : “Inter distr. Adamant. et Sa. de S. Antonio, in vepretis siccis deserti”, August 1818 , (fl), Martius 1508 ( holotype : M-0217529, M-0217530). = Chamaecrista adamantina (H.S. Irwin & Barneby) H.S. Irwin & Barneby, Mem. New York Bot. Gard. 35: 650. 1982 . Cassia adamantina H.S. Irwin & Barneby, Mem. New York Bot. Gard. 30: 57. 1978 . Type :— BRAZIL : Minas Gerais : Diamantina , June 1934 , (fl, fr), Brade 13677 ( holotype : RB-00539426, RB-00545310, isotype: NY-00003703). = Chamaecrista ixodes (H.S. Irwin & Barneby) H.S. Irwin & Barneby, Mem. New York Bot. Gard. 35: 650. 1982 . Cassia ixodes H.S. Irwin & Barneby, Mem. New York Bot. Gard. 30: 59. 1978 . Type:— BRAZIL : Minas Gerais : Itamarandiba, Chapada de Itamarandiba , June 1960 , (fl, fr), Mendes-Magalhães 18053 ( holotype : NY-00003821). = Chamaecrista xanthadena (Mart. ex Benth.) Govaerts, World Checkl. Seed Pl. 3: 14. 1999 . Nom. illeg. = Chamaecrista amphibola (H. S. Irwin & Barneby) Irwin & Barneby (1982: 651) . ≡ Cassia amphibola Irwin & Barneby (1978: 72) , Type:— BRAZIL . São Paulo : in campis, Vila Franca [ca. 47°W , 2 r s], June 1834 , (fl.), Riedel s.n. [ holotype : Sheet 1 (LE00002283!), Sheet 2 (LE00002284!), isotype: NY00003710!]. Syn. nov. FIGURE 21: Chamaecrista setosa : A, B. and C. Diversity of habits and habitats, note the variation in habit and growth and effuse inflorescence; D. Portion of the main stem, showing the plagiotropic leaves and vinaceous trichomes; E. Detail of indumentum of the branch; F. Foliage, note the ascending leaves; G. Leaf. FIGURE 22: Chamaecrista setosa : A. and B. Inflorescences, note the aspect effuse suberect or pending, with main axes green or vinaceous, and bus nutant; C. and D. Detail of Indumentum of the inflorescence and buds; E. and F. Flowers in frontal view, note the sepals externally yellowish with a central spot vinaceous or completely vinaceous, the apex shortly acuminate or acute; G. Fruit. FIGURE 23: Chamaecrista setosa: A. Flowering branch; B. Detail of indumentum of the branch; C. Detail of the indumentum of inflorescence; D. Stipule; E , F , G and H. Leaflets shapes; I. Detail of surfaces of the leaflets; J. Bracts; K. Bracteole; L. Bud; M. Flower in frontal view; N. Sepal; O. Petals; P. Androecium and Gynoecium; Q. Stamen; R. Gynoecium; S. Fruit; T. Detail of Indumentum of the fruit; U. Seeds ( J.A. Oliveira 15 and 110 —UFG). Chamaecrista amphibola , included formerly in Ch. sect. Absus subsect. Absus ser. Setosae , is known only from its typus collection. It was described by Irwin & Barneby (1978) who cited that its could be an intermediate specimen (hybrid) between some taxa belonging to the series Setosae and Ursinae . After its description, Ch. amphibola was never collected again and analyzing the morphology of its typus collection, we concluded that it is more similar to Ch. exsudans from the series Ursinae than other species of Setosae , mainly for having 3 or more pairs of leaflets and abundant stellate trichomes in vegetative and reproductive parts, which led us to consider Ch. amphibola as a synonym for Ch. exsudans . Considering that both species were described in the same work, and that Ch. exsudans is a more collected and known taxon than C. amphibola , we opted for the binomial as valid.