Cob, boughton.
A field guide to the ferns : and their related families of northestern and central north america / by Boughton Cobb. - Cambridge : Boughton mifflin company, c1956. - xviii, 281p. : ill. ; 19cm. - the peterson field guide series. .
includes bibliographical references and index.
Ferns -- North America -- Identification.
Fougères -- Amérique du Nord -- Identification.
587.31 / COF
A field guide to the ferns : and their related families of northestern and central north america / by Boughton Cobb. - Cambridge : Boughton mifflin company, c1956. - xviii, 281p. : ill. ; 19cm. - the peterson field guide series. .
includes bibliographical references and index.
Ferns -- North America -- Identification.
Fougères -- Amérique du Nord -- Identification.
587.31 / COF