Abarema Pittier

Guerra, Ethiéne, Soares, Marcos Vinicius Batista, Morim, Marli Pires & Iganci, João Ricardo Vieira, 2023, Circumscription of Abarema (Leguminosae, Caesalpinioideae, Mimosoid clade), Phytotaxa 601 (1), pp. 51-60 : 53-54

Abarema Pittier

in Trab. Mus. Comercial Venezuela 2: 86. 1927. ≡ Pithecolobium sect. Abaremotemon Benth., London Journal of Botany 3: 203. 1844. Lectotype: Pithecollobiu m auaremotemo Mart. [= Abarema cochliacarpos (Gomes) Barneby & J.W.Grimes ] (designated by Britton & Killip, 1936).

( Fig 1 )

Shrubs and trees without spines; bark reddish, branches pubescent, pulverulent, with conspicuous lenticels; stipules triangular, brown-greenish, usually caducous. Leaves bipinnate, alternate; nectaries sessile, patelliform, situated between all pairs of pinnae and generally in the last pair of leaflets of each pinnae; petiole, rachis and pinnae rachillae with a ferruginous pubescent, pulverulent indumentum, canaliculate; pinnae opposite, one to five jugate, leaflets sessile, opposite, chartaceous or membranaceous, asymmetric, lanceolate, obovate or oblanceolate, indumentum present or not, venation brochidodromous. Inflorescences axillary, homomorphic, capitate racemes; peduncle with a ferruginous pubescent, pulverulent indumentum; bract triangular, pubescent, caducous; bracteoles spatulate, triangular, pubescent, usually caducous; flowers pentamerous; calyx green, campanulate, lobes 5, each lobe with apex acute and pilose; corolla green, campanulate, infundibuliform, lobes 5, each lobe with apex acute and pilose; androecium with many stamens (more than 10), white, exserted from the corolla, filaments partially fused into a tube, the fused portion inserted or exserted from the corolla; anthers dehiscing longitudinally; ovary superior, subsessile, truncate or attenuate at the apex, glabrous or pilose, stigma punctiform. Legumes spiraled, epicarp brown, with a ferruginous pulverulent indumentum, endocarp brown-orange; seeds obovate, bicolored white and dark bluish, with an open pleurogram, in the upper half of the seed, the basal portion of the pleurogram truncate.

Distribution: —The genus occurs in coastal Atlantic Forest, from Rio de Janeiro state in Southeast Brazil to Rio Grande do Norte in Northeast Brazil. In inland Bahia, in Northeast Brazil, it also occurs in Caatinga vegetation ( Fig 2 ).

TWO SPECIES. Abarema cochliacarpos and Abarema diamantina .

Identification key to the species of Abarema

Figures

FIGURE 1. Diagnostic taxonomic characters of the genus Abarema Pittier. A. capitate inflorescences; B. homomorphic flowers in capitate inflorescences; C. spiraled fruit; D. ferruginous pulverulent indumentum on the fruit epicarp; E. portion of the branch with conspicuous lenticels; F. seed bicoloured, the basal portion of the pleurogram truncate. Photos: Coelho, G.P. (A, B), Iganci, J. (D, E), Guerra, E. (C, F).

FIGURE 2. Map of the geographic distribution of the genus Abarema Pittier.