Two new endangered species of Polygala series Trichospermae (Polygalaceae), endemic to the Cerrado domain, Tocantins State, Brazil

José Floriano Barêa Pastore José Floriano Barêa Pastore,Guilherme Medeiros Antar Guilherme Medeiros Antar

doi:10.5852/ejt.2021.762.1459

José Floriano Barêa Pastore José Floriano Barêa Pastore, Guilherme Medeiros Antar Guilherme Medeiros Antar

Open Access

https://doi.org/10.5852/ejt.2021.762.1459

Copy DOI

Abstract

The Cerrado domain is the most diverse savannah biome in the world and a biodiversity hotspot for conservation. Only a few areas of the domain remain well preserved, among them the Jalapão region in Tocantins State, currently is considered the best preserved area of the Brazilian Cerrado. Listed in a recent Angiosperm checklist for the region, there were two species of Polygala series Trichospermae, which were recognized as new by the first author. Polygala bringelii sp. nov., endemic to the Jalapão region, is diagnosed by its obclavate seeds without a ring of trichomes at their base, keel with the crest shorter than the cuculus, and the internal sepals (wings) longer than the capsule. Polygala tocantinensis sp. nov., endemic to Tocantins state, is distinguished by its internal sepals (wings) with two glands near to the rounded apex, and a ring of convergent trichomes at the base of the seeds. The two species are morphologically closest with Polygala trichosperma of sect. Timutua, series Trichospermae, but differs in its corolla and seeds shape and pubescence. An identification key, photographic plates, photos of floral parts under magnification, preliminary conservation assessments, and ecological comments of both species are also provided.

Highlights

The Cerrado domain with an original area of approximately 2 million square kilometers is predominantly located in central Brazil with smaller areas in Bolivia and Paraguay (Ratter et al 1997)
Informal conservation status assessments were based on range area, criterion B of IUCN (2012), using the estimated area of occupancy (AOO) and the extent of occurrence (EOO), both simultaneously calculated using the GeoCAT tool (Bachman et al 2011)
Due to the presence of short racemes, yellowish glands on the floral parts, the erect gynoecium and long pilose seeds, Polygala bringelii sp. nov. and P. tocantinensis sp. nov. are both members of P. sect

Summary

Introduction

The Cerrado domain with an original area of approximately 2 million square kilometers is predominantly located in central Brazil with smaller areas in Bolivia and Paraguay (Ratter et al 1997) It is regarded as the most diverse savannah biome in the world (Forzza et al 2012), with over 12 800 land plant species recognized for Brazil, of which more than 5,100 are endemic (Flora do Brasil 2020). The genus is found mostly in savannah and grassland biomes, and is characterized by the habit of herbs or subshrubs, the calyx persistent in fruit, or, if deciduous, the keel with a crest It is represented in Brazil by 108 species, found in all of its domains, but mainly in the Cerrado (Flora do Brasil 2020). We provide an identification key, photographic plates, photos of floral parts under magnification, preliminary conservation assessments, as well as taxonomic and ecological comments for both species

Material and methods

Results

Discussion