A new species and new records of Leptogium (Ach.) Gray (Collemataceae, Peltigerales) from Rio Grande do Sul State with an identification key for the genus

Abstract Abstract: Specimens of Leptogium collected in ten localities from the State of Rio Grande do Sul were studied. Sixteen species were found of 28 records mentioned to the state, which represents around 57% of the Leptogium diversity known for Rio Grande do Sul. Leptogium exaratum is proposed as a new species. Leptogium atlanticum, L. milligranum and L. vesiculosum are reported for the first time to the state. The lectotype of L. javanicum is reported here and detailed descriptions are provided to the examined specimens. An identification key is showed with all the 28 mentioned species of Leptogium. It is the first published taxonomic key for Leptogium from Rio Grande do Sul, the State with the highest diversity of this genus in Brazil.

摘要：对采自南里奥格兰德州（Rio Grande do Sul）10个采样点的胶衣属（Leptogium）标本开展了分类学研究。本次研究共发现16个物种，占该州已记载的28个物种记录的约57%，覆盖了该州已知胶衣属物种多样性的57%左右。本研究确立一新种：Leptogium exaratum。大西洋胶衣（Leptogium atlanticum）、细粒胶衣（Leptogium milligranum）与囊状胶衣（Leptogium vesiculosum）为该州首次记录的物种。本文指定了爪哇胶衣（Leptogium javanicum）的后选模式标本（lectotype），并对所研究的全部标本提供了详细形态描述。此外，本文编制了涵盖该州已记载的全部28个胶衣属物种的分类检索表，这是首个针对南里奥格兰德州胶衣属物种的正式发表的分类检索表，而该州也是巴西胶衣属物种多样性最高的地区。