1858. Historical Society of Tennessee. Hon. Mem.
1859. Regia Scientiarum Academia Sverica, Stockholm. Foreign Mem.
1859. Imperial Society of Botany, Moscow. Mem.
1859. Russian Society of Horticulture, St. Petersburg. Mem.
1860. Cleaveland Natural History Soc. of Bowdoin College (Maine). Hon. Mem.
1861. Botanical Society of Canada. Hon. Mem.
1862. Imperial Academy of Sciences, St. Petersburg. Corresp. Mem.
1863. Natural History Society of Dublin (union with Dublin University Nat. Sci. Association). Corresp. Mem.
1863. National Academy of Sciences of the United States. Mem.
1865. K. K. Zoologisch-Botanische Gesellschaft in Wien. Mem.