Desert Ironwood
Olneya tesota

LANDSCAPE USE
Medium-sized shade tree.

GROWING CONDITIONS
AN EXPLANAITION OF TERMS USED

SUN full sun, can tolerate reflected heat
WATER rare to moderate—these plants can live on very little water but won’t grow much; they are much faster growing with low to moderate water, can live on rainfall
SOIL tolerant, best with good drainage
HARDINESS hardy to about 20°F
BASIN high zone
CONTAINER not recommended
NUTRITION low
MAINTENANCE very little, remove thorny branches from high traffic areas

ECOLOGY
This is an important keystone species for the Sonoran Desert and has many important relationships with bird, insect, and other plant species. Among some of the more conspicuous associations are bees of many sorts, especially carpenter bees (Xylocopa spp), domestic honeybees (Apies mellifera) and the most abundant bee, a desert digger bee (Centris pallida). Hummingbirds also visit the flowers. Many animals use the seeds for food.

ETHNOBOTANY
Edible seed pods for humans (with proper timing and processing). The wood has been used for all sorts of building purposes, maybe most famously known as the preferred wood for Seri wood carvings. Ironwood is so dense that it does not float, and burns hot for a long time as fuel.

NATURAL DISTRIBUTION
The geolographical limits of this species closely resembles the outline of the Sonoran Desert, proper. Found in desert washes and on low hills often in gravelly to silty soil below 3,000 ft. in Arizona, California, Sonora, and Baja California. Always in well-drained soils.

TAXONOMY AND NAME
This species is in the Fabaceae, legume family. The genus Olneya is monotypic, meaning that there is only one species.
Olneya is named for Stephan Olney (1812-1878) an American botanist, while tesota is a corruption of the Spanis tieso meaning stiff or firm, referring to the wood of the tree.