APA (7th ed.) Citation

National Arboretum (U.S.). (1998). Hydrangea macrophylla 'Nigra': U.S. National Arboretum elite plant : gardens unit. [U.S. National Arboretum, U.S. Dept. of Agriculture, Agricultural Research Service].

Chicago Style (17th ed.) Citation

National Arboretum (U.S.). Hydrangea Macrophylla 'Nigra': U.S. National Arboretum Elite Plant : Gardens Unit. [Washington, DC] (3501 New York Ave., N.E., Washington 20002): [U.S. National Arboretum, U.S. Dept. of Agriculture, Agricultural Research Service], 1998.

MLA (9th ed.) Citation

National Arboretum (U.S.). Hydrangea Macrophylla 'Nigra': U.S. National Arboretum Elite Plant : Gardens Unit. [U.S. National Arboretum, U.S. Dept. of Agriculture, Agricultural Research Service], 1998.