This Province occurs in Tamaulipas only in a small portion of the
Central Plateau physiographic region and occupies the southwesternmost
part of the state.
The vegetation is of two types: Desert or
Mesquite-grassland. The last is like that described for the
Tamaulipan Biotic Province. In the Desert type the dominant
plants are the cactus, _Opuntia leptocaulis_, and yuccas,
_Yucca filifera_ and _Y. potosina_. Subdominants are
mariola, guayule, _Agave lechugilla_, _A. stricta_ or
_Larrea divaricata_. Along stream banks mesquite, _Prosopis
juliflora_, can be found.
No endemic mammals of the Chihuahuan Province are known in
Tamaulipas. Mammals that occur principally in this Province
are: _Dipodomys merriami atronasus_; _D. ordii durranti_;
_Peromyscus melanophrys consobrinus_; _P. difficilis
petricola_; _Onychomys torridus subrufus_; and _Neotoma
albigula subsolana_.