Vascular flora of Lençóis Maranhenses National Park, Maranhão State, Brazil: checklist, floristic affinities and phytophysiognomies of restingas in the municipality of Barreirinhas

ABSTRACT This study presents a floristic survey of the vascular plants of restingas of Lençóis Maranheses National Park, in the municipality of Barreirinhas, Maranhão, Brazil, including descriptions of the principal phytophysiognomies and similarity analyses including other restinga areas in North and Northeastern Brazil. Samples from the study area deposited in the herbaria MG, IAN and MAR were inventoried and fieldwork for the collection of additional botanical samples was undertaken between September 2015 and August 2017. Unweighted pair group method with arithmetic mean (UPGMA) using Jaccard index was used to calculate the similarity among floras of the restingas of the states of Pará, Piauí, Ceará and Maranhão. A total of 289 species in 189 genera and 73 families was recorded, including 56 new occurence records for the state of Maranhão. The richest families were Poaceae, Cyperaceae, Fabaceae, Rubiaceae, Eriocaulaceae and Myrtaceae. Similarity indexes revealed low similarity among the selected areas, suggesting high floristic identity for each area, as well as possible collection bias among the areas.

摘要
本研究针对巴西马拉尼昂州巴雷里尼亚斯市境内伦索伊斯马拉尼昂国家公园的海滨沙生植被（restinga）维管植物开展区系调查，涵盖主要植物群落外貌（phytophysiognomy）的描述，以及针对巴西北部与东北部其他海滨沙生植被区域的区系相似性分析。本研究对馆藏于MG、IAN和MAR标本馆的研究区域标本进行了编目，并于2015年9月至2017年8月期间开展野外考察以采集补充植物标本。采用基于雅卡尔指数（Jaccard index）的算术平均非加权组平均法（UPGMA），计算帕拉州、皮奥伊州、塞阿拉州及马拉尼昂州海滨沙生植被的区系相似性。本研究共记录73科189属289种维管植物，其中包含56项马拉尼昂州新分布记录。物种丰富度最高的科为禾本科（Poaceae）、莎草科（Cyperaceae）、豆科（Fabaceae）、茜草科（Rubiaceae）、谷精草科（Eriocaulaceae）与桃金娘科（Myrtaceae）。相似性指数分析结果显示各选定区域间相似性较低，表明各区域具有较高的区系独特性，同时各区域间可能存在标本采集偏差。