Azaleas and rhododendrons at the National Arboretum.
Contributors: United States. Agricultural Research Service.
Edition: [Rev. Jan. 1974]
Series: Program aid ; no. 491; Program aid (United States. Dept. of Agriculture) -- no. 491.
Publisher: Dept. of Agriculture, Agricultural Research Service
Published: 1974
Place of publication: [Washington]
Language: eng
Subjects: Azaleas.; Rhododendrons.; National Arboretum (U.S.).