"Iris Cohen" wrote in message
...
when the specific epithet derives from a place name, the place name is
Latinised by adding -ense for a feminine name, or -ensis for a masculine
or
neuter generic name. Well, sometimes - I've seen e.g. peruana and I think
peruviana too.

The two endings have entirely different uses. -ense means from. Planta
chinense
or sinense means plant from China. -ana or -anum or -anus means in honor
of. It
can be added to the name of a country or a person. There are many
different
plants named rothschildiana, honoring the Rothschilds, who financed
numerous
botanical expeditions.

There do seem to be quite a few exceptions to this. And the Latin root of
'-anus' only implies 'of' or 'pertaining to', not particularly distinct from
'originating from' (cf. 'montanus', 'montana').
..
E.g I'm sure Aira caryophyllea ssp .armoricana is named because it's found
in Brittany, not particularly to honour the place.
Argemone mexicana?
Genista monspessulana / Acer monspessulanum?
Limonium transwallianum?

Anyway, St. Louis code:
"60D.1. An epithet derived from a geographical name is preferably an
adjective and usually takes the termination -ensis, -(a)nus, -inus,
or -icus." (Which fails to mention '-acus' BTW.) It doesn't seem to make any
usage distinctions between these.


At this point various silly thoughts came to mind:
Acer pseudoplatanus - in honour of a fake philosopher

Matthiola incana - in honour of a lost civilization
Galeopsis ladanum - in honour of a triumph of Soviet engineering