Agalinis marianae (Orobanchaceae), a new endangered species endemic to the Quadrilátero Ferrífero, Minas Gerais, Brazil

ABSTRACT The Quadrilátero Ferrífero (Iron Quadrangle [IQ]), in Minas Gerais, Brazil, exhibits high geological and geomorphological diversity, reflected by its high heterogeneity of vegetation. Its rock outcrops, particularly ironstone, harbor endemic-rich plant communities and contribute substantially to the biodiversity of the biomes they are embedded within the Atlantic Rainforest and Cerrado region. The aim of this study was determining the distribution, phenology and state of conservation of one new species for science with occurrence in the Quadrilátero Ferrífero. Random walks were carried out in the areas of potential occurrence of the species and individuals were collected to allow description. The plant species was identified and categorized as being new to science and known only from this location: Agalinis marianae (Orobanchaceae). This new species is morphologically similar to A. itambensis but can be recognized by the smaller pedicels and the shape of the corolla. The distinct geographic distribution of these species is an additional factor that supports this separation. Here, we describe and illustrate A. marianae, and provide notes on its distribution, habitat, phenology, and conservation status. We also present a key to the species of Agalinis from Minas Gerais.摘要 巴西米纳斯吉拉斯州的铁四角矿区（Quadrilátero Ferrífero，简称IQ）具有极高的地质与地貌多样性，其植被异质性显著体现了这一特征。该区域的岩石露头（rock outcrops），尤以铁质岩（ironstone）露头为甚，孕育了特有种丰富的植物群落，对其所在的大西洋雨林（Atlantic Rainforest）与塞拉多（Cerrado）生物群系的生物多样性贡献显著。本研究旨在明确一种发现于铁四角地区的科学新物种的分布、物候（phenology）及保护现状（conservation status）。研究人员在该物种的潜在分布区域开展随机踏查，并采集植株个体以开展形态描述。经鉴定，该植物为科学新种，且仅知分布于该区域，定名为马里亚纳翅萼草（Agalinis marianae，列当科Orobanchaceae）。该新种在形态上与A. itambensis相似，但可通过较短的花梗（pedicels）与花冠（corolla）形状进行区分。二者截然不同的地理分布格局，是支持其独立成种的又一佐证。本文对马里亚纳翅萼草进行了描述与图示，并就其分布、生境（habitat）、物候及保护现状进行了说明，同时提供了米纳斯吉拉斯州产翅萼草属（Agalinis）物种的分种检索表。