Mimosa arenosa ( Willdenow 1806: 1054 ) Poiret (1810: 66)

Gomes, Aureliana Santos, Rodrigues, Erimágna De Morais, Moura, Débora Coelho, Melo, José Iranildo Miranda De, Ribeiro, Rayane De Tasso Moreira & Queiroz, Rubens Teixeira De, 2022, Fabaceae Lindl. in a Conservation Unit in the Semi-Arid Region of Paraíba, Brazil, Phytotaxa 555 (1), pp. 17-41 : 30-31

20. Mimosa arenosa ( Willdenow 1806: 1054) Poiret (1810: 66)

Trees, branches tomentose, aculeate. Nectary absent. Stipules lateral, acicular. Leaves bipinnate, paripinnate, 14– 18–foliolate, leaflets opposite, oblong, venation actinodromous, translucid punctuation absent. Inflorescence spike, axillary. Flowers sessile, actinomorphic, diplostemonous; calyx gamosepalous, sepals 4, corolla gamopetalous, tubular, whitish, petals 4; androecium dialystaminous, homodinamous, anthers longitudinal; ovary superior, stipitate, pluriovulate. Fruit craspedium, stipitate, linear, plane, margin straight, epicarp glabrous, brown. Seeds not observed.

Examined material:— BRAZIL. Paraíba: Maturéia, Pico do Jabre , 800 m elev., 13 May 2019, fl., Aureliana Gomes 3012 ( HACAM) .

Distribution and ecology:— The species is distributed in Colombia, Venezuela, Mexico and Brazil, where it is distributed from Ceará to Minas Gerais, exclusively associated with the Caatinga domain ( Dourado, 2013; Flora do Brasil 2020). Souza et al. (2021), found this species in Sertão region at Paraíba state.

Phenology:— Registered with flowers in May.

Taxonomic discussion:— Mimosa arenosa can be recognized, mainly, by the arboreous habit, tomentose aculateate branches, inflorescence in spike and by the flat craspedium fruits. Spiciform inflorescence is a feature shares with the other Mimosa species recorded in the study area, with Mimosa arenosa and M. tenuiflora their white flowers vs. pink flowers on Mimosa invisa and M. verrucosa . Mimosa arenosa presents twisted aculeous and flat straight craspedium vs. straighted aculeous and flat corrugate craspedium in M. tenuiflora .