1. A New Family Herbal Richard Phillips, London, 1810, p. 754.
2. Welsh Botanology W. Marchant, London, 1813, p. 171.
3. An Encyclopaedia of Plants Longman, Rees, Orme, Brown, Green and Longman, London, 1836, p. 783.
4. The Domestic Dictionary and Housekeeper's Manual William Strange, London, 1842, p. 160.
5. ; ; ; The Oxford Book of Food Plants Oxford University Press, 1969, p. 190.