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.
Iris,
Central NY, Zone 5a, Sunset Zone 40
"If we see light at the end of the tunnel, It's the light of the oncoming
train."
Robert Lowell (1917-1977)