phytogeography
noun
phy·to·ge·og·ra·phy ˌfī-tō-jē-ˈä-grə-fē 
: the biogeography of plants
phytogeographer
ˌfī-tō-jē-ˈä-grə-fər
noun phytogeographical
ˌfī-tō-ˌjē-ə-ˈgra-fi-kəl
adjective or phytogeographic
ˌfī-tō-ˌjē-ə-ˈgra-fik
phytogeographically
ˌfī-tō-ˌjē-ə-ˈgra-fi-k(ə-)lē
adverb 
Word History
Etymology
probably borrowed from French phytogéographie, from phyto- phyto- + géographie geography, as translation of Danish Plantegeographie or German Pflanzengeographie
Note: The Danish word and the German equivalent were disseminated by the publication of Grundtræk til en almindelig Plantengeographie (1822), and its German translation Grundzüge einer allgemeinen Pflanzengeographie (1823), by the Danish botanist and politician Joakim Frederik Schouw (1789-1852).
First Known Use
circa 1847, in the meaning defined above