Madrean Region
The Madrean Region is characterized by a very distinct
Floristic provinces
The region is subdivided into four
- Great Basin Province
- Californian Province
- Sonoran Province
- Mexican Highlands Province
Great Basin Province
The Great Basin Floristic Province includes most of the Great Basin, as well as the Colorado Plateau, the Snake River Plain, and Arizona north of the Mogollon Rim. It shares much of its flora with the neighboring provinces and has only a few endemic genera. Species endemism is also moderate (about 25%), but is much more considerable in such genera as Astragalus, Eriogonum, Penstemon, Cymopterus, Lomatium, Cryptantha, Chrysothamnus, Erigeron, Phacelia, Castilleja, and Gilia.
The vegetation in the central
Californian Province
The
Sonoran Province
The Sonoran Province comprises arid areas in the southwestern U.S. and northwestern Mexico from
Mexican Highlands Province
The Mexican Highlands Province comprises areas in the
See also
Bibliography
- Thorne, Robert F. Phytogeography of North America North of Mexico. Flora of North America, Vol. 1, Ch. 6.