Quillworts (Isoetes) of the Ottawa DistrictArticle by Daniel F. Brunton and Donald M. Brunton
Trail & Landscape 1999; 33(3): 131-146
Available on the Biodiversity Heritage Library website

“Rather unimpressive in gross appearance… Only when present in large numbers in shallow water are quillworts noticed by many botanists. Even then, most quillwort species look superficially alike.” However, “as with so many things in the natural world, a solution to this seemingly inscrutable biological puzzle seems to have been found behind that apparent mask of sameness.”

This 15-page article begins with a description of quillworts, the importance of hybrids, their unique way of surviving in “demanding habitats,” and advice on how and where to look for quillworts in the Ottawa area.

The short key is based on the appearance of quillwort macrospores. It is followed by a summary of the status and distribution of each of the six taxa known to occur in the Ottawa Valley.