Index to the described species of botrychium
Underwood, L.M.
Index to the described species of botrychium - New York 1903 - 42-55 p. - Contributions from the Department of Botany of Columbia University No. 201 .
Index to the described species of botrychium - New York 1903 - 42-55 p. - Contributions from the Department of Botany of Columbia University No. 201 .