Collinson's life is a microcosm of 18th-cent. natural history. A gardener and naturalist by avocation, he was what we would now call a facilitator in natural science, disseminating botanical and horticultural knowledge during the Enlightenment. He influenced the Comte de Buffon and Linnaeus. He found clients for the Phila. naturalist John Bartram. American plants populated great estates like those of the Dukes of Richmond, Norfolk, and Bedford, as well as the Chelsea Physic Garden, and the nurseries of James Gordon and Robert Furber. Botanic painters such as Mark Catesby and Georg Dionysius Ehret painted American plants in Collinson's garden. He had an unprecedented effect on the exchange of scientific info. on both sides of the Atlantic. Illus.