Mimosa tocantina Taubert, Bot. Jahrb. Syst.
Creators: name: Borges, Leonardo Maurici
name: Pirani, José Rubens
Publisher: name: Zenodo
Year: 2014
Subjects: Biodiversity
Taxonomy
Plantae
Tracheophyta
Magnoliopsida
Fabales
Fabaceae
Mimosa
Mimosa tocantina

description: Mimosa tocantina Taubert, Bot. Jahrb. Syst. 21: 431–432. 1896.
Lectotype (designated by Borges & Pirani 2014):— BRAZIL. Goiás: Habitat in ditione Tocantini superioris in montosis ad Vargem grande, September 1892, fl., E. Ule 2826 (HBG! [also annotated as “3”], isolectotype: P! [only annotated as “3”; “ nos morros da regiao do Tocantins superior, Pizarao” = Ribeirão Pizarão, 14º10’S, 47º’35’W (Barneby 1991)]).
Figs. 2; 7–10.
Mimosa pseudosetosa Marc.F. Simon & C.E. Hughes, Syst. Bot. 35(2): 279, 281, fig. 1.B–C; fig. 4, syn. nov. TYPE:— BRAZIL. Goiás: Cavalcante, Vila Engenho, caminho para cachoeira Santa Bárbara, campo sujo, solo arenoso, 13º32’ S 47º29’ W, 1070 m, 12 October 2002 (fl, fr imm), M. F. Simon 453 (holotype: UB!, isotypes: CEN!, FHO, K!).
Mimosa longepedunculata sensu Barneby (1991: 407–408), except for the type (Ule 2830).
All specimens of Mimosa tocantina listed below where already described either by Barneby (1991: 407–408) as M. longepedunculata or by Simon et al. (2010: 279, 281–282), as M. pseudosetosa. Barneby’s description fits exclusively specimens of M. tocantina and may be complemented by the description and illustrations of Simon et al. (2010). These latter authors were unaware of M. longepedunculata sensu Barneby, and described it as new species based on flowering specimens mainly collected at the northern portion of Chapada dos Veadeiros. Hence, a full description is not presented here and only complementary information about the species is given below.
Examined specimens: — BRAZIL. Goiás: Alto Paraíso de Goiás, Chapada dos Veadeiros, ca. 25 km N of Alto Paraíso, 1250 m, 23 March 1971 (fl, fr imm), H. S. Irwin et al. 33032 (K!, NY!, UB!); Alto Paraíso de Goiás, Chapada dos Veadeiros, ca. 25 km by road N of Alto Paraíso, 1700 m, 8 March 1973 (fl), W.R. Anderson et al. 6660 (NY!, UB!); Alto Paraíso de Goiás, Chapada dos Veadeiros, ca. 35 km north of Alto Paraíso de Goiás (formerly Veadeiros), 1000 m, 14 March 1969 (fl, fr imm), H.S. Irwin et al. 24308 (K!, NY! [2 sheets], UB!); Alto Paraíso de Goiás, 50 km ao norte de Alto Paraíso rumo à Teresina de Goiás, 13º50’ S, 47º15’ W, 1000 m, 7 January 2007 (fl), M. F. Simon 871 (FHO, UB!); Cavalcante, cerca de 30 km ao norte de Cavalcante, caminho entre Vila Engenho e cachoeira Santa Bárbara, 13º32’27” S, 47º29’17” W, 1050 m, 5 January 2007 (fl), M. F. Simon 864 (CEN!, FHO, HUEFS!, K!, UB); Cavalcante, Chapada dos Veadeiros, 15-40 km W and N of Alto Paraíso, 1250–1500 m, 20 March 1975 (fl), W. R. Anderson et al. 11478 (K!, NY!, UB!); Cavalcante, Chapada dos Veadeiros, ca. 40 km N of Alto Paraíso, 1250, 24 March 1971 (fl, fr imm), H. S. Irwin et al. 33123 (NY!, UB!); Cavalcante, estrada de chão entre Cavalcante e Araí, 13º35’59” S, 47º31’30” W, 1190 m, 13 April 2004 (fl), R. C. Mendonça et al. 5528 (BAB, IBGE!, UB!); Cavalcante, Chapada dos Veadeiros, Rodovia BR 010, Teresina de Goiás-Alto Paraíso de Goiás, ca. de 24 km de Teresina (também a 34 km S de Teresina de Goiás), margem esquerda da estrada, 13º53’04.6” S 47º20’54.1” W, 1234 m, 23 March 2012 (fr), L.M. Borges et al. 594 (SPF!). Teresina de Goiás, 24 km by road S of Teresina, ca. 1250 m, 16 March 1973 (fr), W.R. Anderson et al. 7190 (K!, NY!, UB!); [Teresina de Goiás], Chapada dos Veadeiros, 54 km depois de Alto Paraíso, 18 March 1976 (fr imm), J. Semir 757 (K! [2 sheets], NY!, UB!, UEC); Teresina de Goiás, Rodovia GO-118, 5– 8 km N de rio das Almas, 14 February 1990 (fl), G. Hatschbach 53971 (K!, MBM, NY!, UB!).
Distribution and habitat: — Mimosa tocantina is endemic to Chapada dos Veadeiros, occurring in open formations, generally “campos rupestres” with rock outcrops, between 1000 and 1700 m in elevation. The species usually forms small aggregated populations with individuals surrounded by grasses. Soils are sandy or sandy and rocky, and may become waterlogged during the rainy season. Although wrong about the species identity, Simon et al. (2010), who studied specimens collected at Cavalcante and Terezina de Goiás municipalities, were correct in their prediction about its larger distribution area. When complemented by the collections studied by Barneby (1991), it extends farther to the south of Chapada dos Veadeiros, reaching Alto Paraíso de Goiás municipality (Fig. 10).
Conservation status: —EN. According to GeoCAT analysis results (EOO = 1043.90 km 2; AOO = 44 km 2), the species may be classified as Endangered.
Flowering and fruiting: —Flowering specimens of Mimosa tocantina have been collected in September, October and from January through March. Specimens with mature and immature fruiting were collected only in March. It is probable that the individuals may still bear fruits until June and July, at least, but the lack of the showy pink flowers when the fruits are mature may make it difficult to visualize this procumbent shrub among the grasses and, thus, its collection.
Etymology: —The species was named after the region where it was collected by Ule, specifically, the headwaters of the Tocantins River, particularly near the Tocantinzinho River area. Amusingly, many new species from different genera published in Taubert (1896) were given just the same name.
Notes: —The overall habit of Mimosa tocantina recalls that of M. albolanata, which does not occur at Chapada dos Veadeiros, but is common in other areas of Goiás and Minas Gerais states, as well as the Distrito Federal (Barneby 1991). However, M. tocantina, besides its long peduncles, is distinguished by the presence of orange-reddish setae concentrated at the tips of shoots and in leaves under development (not present in M. longepedunculata). M. irwinii, M. speciosissima and M. splendida, all occurring at Chapada dos Veadeiros, also have the same kind of orange-reddish indumentum, but in them it is distributed all over the plants and not restricted to particular areas.
description: Published as part of Borges, Leonardo Maurici & Pirani, José Rubens, 2014, When the old guys knew better: The true identity of Mimosa longepedunculata and reestablishment of M. tocantina (Leguminosae, Mimosoideae), pp. 261-278 in Phytotaxa 181 (5) on pages 274-275, DOI: 10.11646/phytotaxa.181.5.2, http://zenodo.org/record/5152478