RESUMO

Studies of the genus Pinnularia Ehrenb. are only incipient in central-western Brazil, especially in Goiás. Only 20 of the 170 taxa known from Brazil were recorded in this state until now. A taxonomic study of Pinnularia from Lago dos Tigres (Tocantins-Araguaia River Basin) recorded 20 specific and infraspecific taxa, distributed in 17 species, including P. instabilis whose lectotype is designated here. Only P. meridiana var. meridiana was previously recorded in aquatic systems of the state. Eighteen taxa are newly recorded for Goiás, and one is the first record in Brazil. The Pinnularia flora from Lago dos Tigres contains nine taxa in common with the Amazon River Basin flora, and seven other taxa that occur elsewhere in the Paraná River Basin.

O gênero Pinnularia Ehrenb. é incipientemente estudado na região Centro-Oeste brasileira, especialmente em Goiás. Somente 20 de 170 táxons conhecidos no Brasil foram registrados nesse estado até agora. Nesse estudo, objetivou-se a realização de estudos taxonômicos de Pinnularia do Lago dos Tigres (Bacia Tocantins-Araguaia). Vinte táxons em nível específico e infraespecífico, distribuídos em 17 espécies, foram observados e caracterizados aqui, incluindo P. instabilis cujo lectótipo foi designado aqui. Somente P. meridiana var. meridiana foi primeiramente registrada em sistemas aquáticos do estado. Dezoito táxons constituíram citações pioneiras para o estado de Goiás e um foi o primeiro registro de ocorrência para o Brasil. A flora de Pinnularia do Lago dos Tigres apresentou nove táxons comuns com a Bacia Amazônica e outras sete foram comuns è Bacia do Paraná.

RESUMO

The flora of diatoms from Brazil has been studied by several authors from the beginning of the 19(th) up to now. Some of the old lists and descriptions are unknown or have been ignored by Brazilian researchers and the situation of the names cited was not assessed. Here we compiled a list of 101 taxa of diatoms from Brazil registered by Christian Gottfried Ehrenberg during the 19(th) century. We checked the current nomenclatural status of those taxa and lectotypified species from Brazil described by this author. For this, we accessed the Ehrenberg collection in the Museum für Naturkunde, Berlin, Germany, where 11 samples from Brazil studied by Ehrenberg are housed and published in different papers. Using these samples, we found 101 taxa (specific and infraspecific) published by Ehrenberg from Brazil. Five species (Eunotia bidens Ehrenb., Eunotia depressa Ehrenb., Eunotia elephas Ehrenb., Pinnularia microstauron Ehrenb., and Terpsinoe brasiliensis Ehrenb.) were new descriptions and were lectotypified here. The other species cited for Brazil were described initially from other places. However, 23 names were invalid and one illegitimate.