Shrubs, 0.5-3m tall, widely spaced, usually with bare ground between. Growth occurs during spring (or rarely in summer or fall) if rainfall is sufficient. Growth is prevented by cold in winter and limited by drought in other seasons. Many species of ephemeral herbs may flower in late March and April if the winter rains are sufficient. Other, less numerous species of annuals appear following summer thundershowers. This is the basic creosote shrub of the Mojave Desert, dominated by Larrea tridentata and Ambrosia dumosa.
SITE FACTORS:
Well-drained secondary soils with very low available water holding capacity on slopes, fans, and valleys rather than upland sites with thin residual soils or sites with high soil salinity. Winter temperatures often below freezing. Intergrades at higher elevations with Shadscale Scrub (36140), or Joshua Tree Woodland (73000); at lower elevations or more osmotic sites with Desert Chenopod Scrub (36100).
DISTRIBUTION:
Extensive from the Death Valley region southward across the Mojave Desert to the little San Bernardino Mountains, eastward to northwestern Arizona and southern Nevada. The dominant plant community below 3,000 or 4,000 feet (910 or 1210m) in this region.
UPDATE: 10/86
Source: Holland, 1986
Digital Text: NatureBase