Mexico’s diverse landscape and fickle rainfall have sculpted its wide range of plant forms. Botanists recognize at least 14 major Mexican vegetation zones, seven of which occur in the Puerto Vallarta [1] region.
Directly along the coastal highway, you often pass long sections of three of these zones: savanna, thorn forest, and tropical deciduous forest.
Links:
[1] http://www.moon.com/destinations/puerto-vallarta/puerto-vallarta