The state has a great diversity due to the large number of microclimates found and dramatic varying terrain. The flora throughout the Sierra Madre Occidental mountain range varies with elevation. Pine (Pinus) and oak (Quercus) species are usually found at an elevation of 2,000 m (6,560 ft) above sea level. The most common species of flora found in the mountains are: Pinus, Quercus, Abies, Ficus, Vachellia, Ipomoea, Acacia, Lysiloma, Bursera, Vitex, Tabebuia, Sideroxylon, Cordia, Fouquieria, Pithecellobium. The state is home to one of the largest variation species of the genus Pinus in the world. The lower elevations have a steppe vegetation with a variety of grasses and small bushes. Several species of Juniperus dot the steppe and the transition zone.

The state has great diversity thanks to the large number of what?