Olneya tesota

Accession Count: 41
Common Name: ironwood
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Family Name: Fabaceae
Botanical Name: Olneya tesota
Sub Species:
Characteristics: O. tesota grows to twenty-five feet tall. Its exfoliating bark is gray to white. Leaves and twigs are covered with small hairs, which serve to protect the tree from the worst of the hot sun. Leaves are dull green, with a pinnate leaf arrangement, divided into six to sixteen leaflets. Small spines can be curved or straight. Flowers are pea-shaped and pale pink to purple. Dark brown, two inch seed pods develop in the summer.
Compound: Oln tes
Geographic Origin: Desert Southwest
Ecozone Origin: Nearctic
Biome Origin:
Natural History: Ironwood is the tallest growing tree in the Sonoran Desert and provides a much needed micro-habitat for many desert species. It is most commonly found at elevations below 2,500 feet. It is also the only species in its genus.
Cultivation Notes: The ironwood It is a drought deciduous tree, during dry periods it will shed its leaves to preserve water and conserve its energy for flowering and regeneration after the spring rains. It has a moderate growth rate and requires very little water. The ironwood tree does well in full sun and is hardy to 15℉.
Ethnobotany: Ironwood trees are the source of very dense, hard wood (which burns hot and does not float). Native cultures in both Arizona and Sonora made use of the wood for building and carving of bowls, etc. Ironwoods are “nurse” trees in the Sonoran Desert . Animals gather in the shade during the hottest months and other cacti and small shrubs utilize the tree's canopy as shelter from the sun. Like other members of the family Ironwood, it is a tree that gathers nitrogen from the soil, so leaf litter and seeds are particularly rich in nutrients.

Ironwood flowers and seeds are edible. Desert Ironwood flowers can be eaten raw in salads or candied for use in desserts. Although the seeds can be eaten raw, both green and dry/brown stages of seeds may be most easily digested when blanched, sprouted or cooked. The flowers bloom in late April-May and seed pods set in June-July. The pods have a slightly sweet and nutty flavor and become more flavorful when left to ripen on the tree. When they are ripe, they are easier to gently shake free from the limbs. If harvesting green pods, plunge the pods into boiling water and then transfer to ice water to clean them. Drain, dry and package them in sealed plastic (anaerobic) containers marked with the date of harvest. 

If harvesting dry, brown pods, remove the seed into a clean sheet of paper or fabric. Press (or step on) the pods gently to crush the dry pods. Winnow out the seeds and place them in a sealed container in the freezer for two days to prevent bruchid-beetle infestation. Store in the freezer until use or take them out, dry thoroughly and then store in a sealed jar.

Height: 20 - 50 feet
Width: 20 - 50 feet
Growth Rate: Slow Growing
Grow Season: Summer
Flower Season: Spring
Color: Lavender
Function: Shade
Allergen: Non-allergenic
Toxicity: Benign
Hardy: Semi-hardy
Water Use: Low water Use

1. Desert Harvesters
2. Mielke, Judy. Native Plants for Southwestern Landscapes. University of Texas Press, 1993.


Olneya tesota