Isoetes nana, a new species from the coastal mountains of southeastern Brazil.

Jovani Pereira,Thomas Stutzel,Christian Schulz

doi:10.3897/phytokeys.89.20171

Abstract

Isoetes nana, a new species from the coastal mountains of southeastern Brazil (Serra de Itatiaia), is described, illustrated and compared to similar species. This species can be distinguished from similar species by a set of characters that include 5–15 small erect leaves reaching only up to 3.5cm long, megaspores rugulate (rarely laevigate or obscurely cristate) and microspores sparsely echinate. We include a key to identify this new species and spore images for all species that are discussed in this study. Isoetes nana is known only from the type locality, where it was reported to occur in small ponds on rocky outcrops at high elevations. We suggest it should be classified as a data deficient species based on the IUCN criteria.

Highlights

The lycophytes genus Isoetes is a heterosporous plant group occurring as aquatic in lakes, temporary ponds, streams, or terrestrial in wet soils (Pfeiffer 1922; Taylor and Hickey 1992)
In this study, we provide a formal description of the species and a key to identify this new species and similar taxa
Fieldwork was carried out by Ernst Heinrich Georg Ule (1854–1915), a German botanist and botanical explorer of the Amazonas and the Brazilian highlands (Stafleu and Cowan 1986), who collected the materials in March 1894 in Serra do Itatiaia, southeastern Brazil

Summary

Introduction

The lycophytes genus Isoetes is a heterosporous plant group occurring as aquatic in lakes, temporary ponds, streams, or terrestrial in wet soils (Pfeiffer 1922; Taylor and Hickey 1992). Type specimens of all species of Isoetes analysed in this study were consulted.

Results

Conclusion