Zion National Park has the richest and most diverse plant flora of any park in Utah with over 1,000 different species. Much of the parkäó»s diversity is derived from its location at the junction of the Colorado Plateau, Great Basin, and Mojave desert ecosystems. The Mohave flora is very limited in the park, being found primarily in the extreme southwest corner in the Coal Pits Wash and Petrified Forest areas. These low desert areas appear barren and austere during much of the year, but in springtime (especially after a wet winter) the area is covered by delicate wildflowers äóñ including short-lived annuals, prickly cacti, and flowering shrubs. April is the optimal time to visit this corner of the park before temperatures become too hot and while the short-lived floral beauty is still at its peak.