When published in 1993 The Genus Arum (Boyce, 1993) presented for the first time in 70 years, and ever in English, a tool to identify with some degree of confidence all of the 25 Arum species and their subordinate taxa then recognized. Inevitably since publication there have been changes in species delimitation as well as new discoveries, such that the species tally for Arum now stands at 28. Changes of note since 1993 include the recognition of two species treated then at subspecific rank within A. orientale Bieb. [A. longispathum Reich. & A. sintenisii (Eng!.) P. C. Boyce] while a further species [A. alpinariae (K. Alpinar & R. R. Mill) P. C. Boyce], treated then as a subspecies of A. elongatum Steven, is formally raised to the level of species in this paper. Additional study has resolved a number of issues including application of names for the species hitherto called A. alpinum Schott & Kotschy and the status of subordinal taxa in A. italicum Miller. These are all detailed below together with sundry other observations. While much work remains to be done on Arum it seems a worthwhile exercise to present an overview of these changes wrought in the past decade and to cast some pointers for work that still remains to be tackled.