Nick Maclaren wrote:
[...]
No. The Phaseolus species ARE American, and were imported in the
16th
century. The classical Latin terms are for the Vicia faba
varieties
(and possibly for some of the species we rarely grow, but are
common
in India). [...]

I'm handicapped here by owning only the old Lewis and Short, not the
more up-to-date Oxford Latin Dictionary. L&S calls _faba_ the
"horse-bean" (_vicia_ is just vetch, of course); OED isn't specific
about what a "horse-bean" was, so can I assume it was the field bean?
The L&S sources do seem to make a distinction from _phase[o]lus_: I
wonder what they had in mind.

--
Mike.