James Buchanan was a gardener, florist and nurseryman active, particularly in south London, England from the 1790s to the 1820s. In 1795 Buchanan was based at 7 Bowyer Place, Camberwell Road, London, England. He later went into partnership with Henry Oldroyd in 1812 and was especially noted for industriously collecting rare plants.
Sources:
Desmond, Ray, Dictionary of British and Irish Botanists and Horticulturists (London: Taylor & Francis, 1994), p. 113.