Stock Photo: Gum arabic tree, Acacia nilotica. Handcoloured copperplate engraving from a botanical illustration by James Sowerby from William Woodville and Sir William Jackson Hooker's "Medical Botany," John Bohn, London, 1832. The tireless Sowerby (1757-1822) drew over 2, 500 plants for Smith's mammoth "English Botany" (1790-1814) and 440 mushrooms for "Coloured Figures of English Fungi " (1797) among many other works.