On Polystichum aleuticum C. Chr. a New North American Species.
Christensen, Carl..
On Polystichum aleuticum C. Chr. a New North American Species. - Copenhague - American fern Journal ; Vol 28 - Nº 3 .
On Polystichum aleuticum C. Chr. a New North American Species. - Copenhague - American fern Journal ; Vol 28 - Nº 3 .