Taxonomic and geographic studies in North America ferns
By: F.K. Butters
Series: Contributions from the Gray Herbarium of Harvard University -- no. 51
Publisher: Gray Herbarium of Harvard University
Published: 1917
Place of publication: Cambridge, MA
Language: eng
Number of pages: 216
Subjects: Ferns -- North America; Ferns -- North America -- Classification
Table of contents: value: 1. The genus Athyrium and the North American ferns allied to A. Filix-femina; value: 2. Botrychium virginianum and its American varieties