Robert Donald, junior was a nurseryman, active in the 19th century, based at the Goldworth Nursery in Woking, Sussex, England. He was the son of nurseryman Robert Donald, senior (born around 1769, died 1854) to whom he was later partnered in 1842. Doanld was also an associate of John Claudius Loudon. He planted trees at Brookwood Cemetery, Surrey.
Sources:
Desmond, Ray, Dictionary of British and Irish Botanists and Horticulturists (London: Taylor & Francis, 1994), p.212.