The plant-book : a portable dictionary of the vascular plants utilizing Kubitzki's the families and genera of vascular plants (1990- ), cronquist's an integrated system of classification of flowering plants (1981) and current botanical literature arranged largely on the principles of editions 1-6 (1896/97-1931) of Willis's A dictionary of the flowering plants and ferns - Mabberley, David J. (Cambridge University Press, 1997)