One last bit of possibly incorrect knowledge, when the specific epithet
derives from a place name, the place name is Latinised by adding -ense
for a feminine(?) generic name, or -ensis for a masculine or neuter(?)
generic name. Well, sometimes - I've seen e.g. peruana and I think
peruviana too.

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Rec 60D. I am not sure about "-ensis" versus "-ana", etc. It is either
size ("havanensis" and "cubana", not "havanana" and "cubensis") or
linguistic (classical geograpical features get an "-ana", etc ending also
those with classical sounding names).

BTW: You are forgetting about geographical adjectives ("saharae")! :^)

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Oops, slip!
Should be: "You are forgetting about geographical GENITIVES ("saharae")!"

PvR