Desert ironwood, Tesota, Palo de hierro
USDA Symbol: OLTE
USDA Native Status:
Spiny evergreen tree with short trunk and widely spreading, rounded, dense crown often broader than high and with numerous purplish, pea-shaped flowers in late spring. Desert-ironwood is a broad-crowned evergreen attaining 30 ft. in height with a trunk diameter of 1-2 ft. The branches are armed with spines, and the bark is thin and scaly. The foliage, evergreen except during cold winters, is pinnately compound and covered with grayish-white hairs. Flowers, occuring in axillary racemes before the new leaves, are showy and pale, rose-purple in color.
Tesota is the single species of its genus named for Stephen Thayer Olney (1812-78), a businessman and botanist of Rhode Island. The name Tesota is derived either from a Spanish word for stiff, tieso, or from a Southwestern indigenous word for the tree. A characteristic and common desert tree, it is regarded as an indicator in selecting favorable sites for citrus orchards, since it grows only in subtropical areas with warm, mild winters. It is known locally as Ironwood and in Spanish as palo de hierro. The hard, dark brown wood with thin, yellow sapwood is easily polished but dulls tools used to work it. It is made into novelties such as bowls and small boxes and is excellent fuel. It is one of the heaviest native woods; only Leadwood (Krugiodendron ferrum (Vahl) Urban), a small tropical tree of southern Florida, is heavier. The beanlike seeds can be roasted and eaten. Desert animals also consume the seeds, and livestock browse the foliage. A parasitic mistletoe on the branches, with reddish, juicy berries, attracts birds, such as the phainopepla; the birds in turn spread the sticky seeds of the parasite to other trees, mostly in the legume family.
From the Image Gallery
Plant CharacteristicsDuration: Perennial
Size Class: 12-36 ft.
Bloom InformationBloom Color: Pink , Purple
Bloom Time: Apr , May
DistributionUSA: AZ , CA
Native Distribution: S. AZ, s.e. CA, Sonora & Baja CA
Native Habitat: Foothill washes; low desert areas
Growing ConditionsWater Use: Low
Light Requirement: Sun
Soil Moisture: Dry
CaCO3 Tolerance: High
Soil Description: Rocky or sandy soils.
BenefitUse Wildlife: Seeds eaten by desert animals; plant browsed by bighorns.
Conspicuous Flowers: yes
PropagationDescription: Propagation by seed is possible. Seedlings damp-off readily.
Seed Collection: The fruit is a legume pod with black seeds.
Seed Treatment: Fresh seeds require no treatment. Stored seeds should be soaked in water or scarified before seeding.
Commercially Avail: yes
Find Seed or Plants
Find seed sources for this species at the Native Seed Network.
View propagation protocol from Native Plants Network.
From the National Organizations DirectoryAccording to the species list provided by Affiliate Organizations, this plant is on display at the following locations:
Native Seed Network - Corvallis, OR
BibliographyBibref 995 - Native Landscaping from El Paso to L.A. (2000) Wasowski, S. and A. Wasowski
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Recommended Species Lists
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Additional resourcesUSDA: Find Olneya tesota in USDA Plants
FNA: Find Olneya tesota in the Flora of North America (if available)
Google: Search Google for Olneya tesota
MetadataRecord Modified: 2011-03-28
Research By: TWC Staff