Lycophytes of the Chapada das Mesas National Park, Cerrado, Maranhão, Brazil

Abstract: Despite an increase in studies involving lycophytes and ferns in recent years, Maranhão is still one of the northeastern states with a poorly known flora, mainly due to low sampling. For Chapada das Mesas National Park, a protected conservation unit in the Cerrado maranhense with phytophysiognomies that favor floristic diversity, there are no floristic studies about lycophytes. This study aimed to conduct the floristic inventory and taxonomic study of lycophytes in Chapada das Mesas National Park. Three collection expeditions, of three days each, were made between March 2017 and June 2018. Three families of lycophytes represented by three genera and six species were identified in the study area. The most diverse family was Selaginellaceae with four species: Selaginella conduplicata, S. erythropus (Mart.) Spring, S. radiata (Aubl.) Baker and S. simplex Baker. The other two families, Isoëtaceae and Lycopodiaceae, had one species each, Isoëtes sp. and Palhinhaea cernua (L.) Franco & Vasc. This study also reports two new record for the Brazilian Cerrado phytogeographic domain, S. conduplicate and S. radiata, of which the first is a new record for Maranhão State. Most specimens were found in riparian forest on rocky outcrops.

摘要：尽管近年来石松类植物（lycophytes）与蕨类植物的相关研究数量有所增长，但马拉尼昂州（Maranhão）仍是巴西东北部植物区系认知程度较低的州份之一，这主要源于采样强度不足。针对位于马拉尼昂塞拉多（Cerrado maranhense）、拥有利于植物区系多样性发育的植物群落外貌（phytophysiognomies）的保护保育单位（protected conservation unit）——查帕达达斯梅萨斯国家公园（Chapada das Mesas National Park），目前尚无针对其境内石松类植物的区系研究。本研究旨在开展该国家公园内石松类植物的植物区系调查（floristic inventory）与分类学研究（taxonomic study）。2017年3月至2018年6月期间，共实施3次为期3天的采集考察。研究区域内共鉴定出石松类植物3科、3属、6种。物种丰富度最高的科为卷柏科（Selaginellaceae），包含4个物种：卷柏（Selaginella conduplicata）、红卷柏（Selaginella erythropus (Mart.) Spring）、辐射卷柏（Selaginella radiata (Aubl.) Baker）以及单叶卷柏（Selaginella simplex Baker）。其余2个科分别为水韭科（Isoëtaceae）与石松科（Lycopodiaceae），各含1个物种：水韭属未定种（Isoëtes sp.）以及垂枝扁石松（Palhinhaea cernua (L.) Franco & Vasc.）。本研究同时报道了巴西塞拉多植物地理区（phytogeographic domain）的2个新记录物种：S. conduplicata与S. radiata，其中前者为马拉尼昂州的新记录物种。绝大多数标本采集于岩石露头（rocky outcrops）处的河岸林（riparian forest）。