Isoetes prototypus, a new diploid species from eastern Canada

Abstract

A new species of Isoetes, I. prototypus from eastern Canada, is described. The morphology of the megaspores shows some similarity to those of acadiensis and I. hieroglyphica, but the microspores have a spinulose network on their surface. The plants have straight and rigid leaves that resemble some forms of I. macrospora. The species is diploid (2n = 22) and is found deep (± 2 m) in cool lakes in New Brunswick and Nova Scotia. Key words: Isoetes, new species, diploid, Canada, SEM.