RUHSAM M. Coryphantha. R.F. Dicht & A.D. Lüthy. Berlin, Heidelberg: Springer-Verlag. 2005. 200pp, colour plates, drawings, maps. ISBN 3 540 22306 1. £61.50 (hardback). Edinburgh J. Bot. 2005;61(2-3):201-202. doi:10.1017/S0960428605290273