I think "flora" is the word you want.
There's an online checklist and some interactive keys at:
http://www.efloras.org/flora_page.aspx?flora_id=101
I also find reference to a Flora of Taiwan, along with a 2nd edition
of the same work. Ah, yes, here it is. A six volume work, Flora of
Taiwan, by the Flora of Taiwan Editorial Committee, Epoch Publishing,
1975-
This is going to be a technical taxonomic work rather than a handbook
or guidebook, but it would be a place to start. Perhaps your library
has it or can borrow it for you.
M. Reed
Texas A&M University.