A new species of Rhynchospora section Pluriflorae (Cyperaceae) from the southwestern edge of the Brazilian Amazon

Abstract

A new species of Rhynchospora (Cyperaceae) only known from the Parecis plateau, on the southwestern edge of the Brazilian Amazon, is described here. Rhynchospora parecisensis was found growing only in open environments of deciduous seasonal forest and savanna enclaves in the midst of seasonal evergreen forest, in the state of Mato Grosso, western Brazil. Rhynchospora parecisensis differs from the other species of Rhynchospora sect. Pluriflorae subsect. Subebracteatae by the distally puberulent to pubescent glumes. The new species resembles Rhynchospora acanthoma, but differs from it by the subtriangular to quadrangular scapes in cross-section and the distally puberulent to pubescent glumes, with ciliate to ciliolate margins. Taxonomic comments, illustrations and a distribution map are also provided.