Citing a revision of a 2nd edition book

I'm wondering how to reference a book The Jepson Manual, 2nd Edition shown below.

Baldwin, B. et al. (ed.). 2012. The Jepson Manual, Vascular Plants of California, Rev. 2, 2nd ed. University of California Press.

I wondering about citing the revisions which are available on-line at eflora. There are now two second revision of this second edition. Should the revisions be listed in the citation as above or some other way? And should I keep the book date at 2012 even though the online revision 2 was 2014.

Thanks,

David