Loudon, John C.: Arboretum et fruticetum britannicum : or, the trees and shrubs of Britain, native and foreign, hardy and half-hardy, pictorially and botanically delineated, and scientifically and popularly [...] : . From Asclepiadaceæ / by J.C. Loudon :. London. London : printed for the Author : and sold by Longman, Orme, Brown, Green, and Longmans : the partially coloured and coloured copies, by James Ridgway and Sons, 1838