Helena Attlee's 'The Land Where Lemons Grow' dropped on my doorstep for Christmas. It is a delightful and absorbing account of citrus growing in Italy. There are tempting descriptions of citrus recipes, just right to warm these freezing winter days and an excellent historical account of citrus growing in Italy, not the most obvious place for growing citrus. Another kind of plant mania.
Regarding this thread of citrus taxonomy, Attlee gives David Mabberley's opinion that citrus taxonomy is 'taxonomic havoc' p.35
The full Mabberley refeence is, David Mabberley, 'Citrus (Rutaceae):A Review of Recent Advances in Etymology, Systematics and Medical Applications', Blumea, Vol. 49 (10 December), p.484