Washington: G.P.O., 1898.

New York, Holt, 1909.

Washington,Govt. Print. Off.,1902. | New York Botanical Garden, LuEsther T. Mertz Library

Washington,Govt. Print Off.,1899. | New York Botanical Garden, LuEsther T. Mertz Library

1921 publication

Washington :Govt. Print. Off.,1899. | University of Connecticut Libraries (archive.org

written work by Frank Hall Knowlton

Washington :Govt. Print. Off.,1914. | New York Botanical Garden, LuEsther T. Mertz Library

Washington: Govt. Print. Off., 1893.

Washington, Govt. print. off., 1922.

Washington,Govt. print. off.,1922. | New York Botanical Garden, LuEsther T. Mertz Library

Washington: Govt. print. off., 1898.