During the seventeenth and eighteenth centuries, bastard, freak, rogue, monster, mongrel and mule described horticultural oddities. Gardens were full of such things; some were picked up from nature and transplanted, others were found spontaneously growing in gardens. These plants were catalogued and described by generations of naturalists and gardeners, whilst the great and the good would pay vast sums for choice specimens. However, it was left to natural philosophers to conjecture with ideas, such as spontaneous generation and transmutation, about how they were formed. Unlike many of his contemporaries, Richard Bradley, an impoverished English naturalist, had little interest in cataloguing, describing and classify nature, he was interested in the practical aspects of how plants work and how they interact with each other and with animals.
In 1694, the German physician Rudolf Camerarius produced experimental evidence for the controversial idea plants were capable of sexual reproduction. By 1717, Bradley, in his essay Of the Generation of PLANTS, took the controversy further and drew attention to the interspecific crossing studies the curious nurseryman Thomas Fairchild of Hoxton had made in the genus Dianthus. Bradley, a champion of plant breeding, immodestly described himself as having a 'Natural Bent of Genius' and went on to become Professor of Botany at Cambridge University towards the end of his short life.
In Bradley's words, 'the Carnation [Dianthus caryophyllus] and Sweet William [Dianthus barbatus] are in some respects alike; the Farina [pollen] of the one will impregnate the other, and the Seed so enliven'd will produce a Plant different from either, as may now be seen in the Garden of Mr. Thomas Fairchild of Hoxton, a Plant neither Sweet William nor Carnation, but resembling both equally, which was raised from the Seed of a Carnation that had been impregnated by the Farina of the Sweet William'. Two of Fairchild's mules have survived in the herbaria of Oxford University and the Natural History Museum, London. These specimens are morphologically different. Fairchild must have created Dianthus mules more than once or, over the last three centuries, the Oxford specimen has become mislabeled.
Fairchild had artificially created first generation sterile Dianthus hybrids, discovered familiar horticultural variation could be explained and showed rational plant breeding was possible. Fairchild the businessman perhaps also discovered a new way of generating client-tempting variation. Bradley concluded hybrids formed in nature and special care was needed when seed, especially from trees, was selected for planting purposes.
Leapman M 2000. The ingenious Mr Fairchild. The forgotten father of the flower garden. St. Martin's Press.