by Robert T. Clausen
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Variation of species of Sedum of the Mex...
Biennial species of Sedum of the Sierra ...
On the status of Botrychium dissectum va...
Najas arguta in Central America and its ...
Northeastern limits of the known range o...
Hybrids of the eastern North American su...
Adumbratio Florae Aethiopicae
Ophioglossaceae
Gametophytes of ophioglossaceae
The Botrychiaceae of Alberta
Ophioglossum, Rollandia, and Scaevola
New family and combinations of ferns