Flower profile

Desert ironwood

Olneya tesota

Desert ironwood (Olneya tesota) is a shrub or small tree in the Fabaceae family, native in the lower 48 states, blooming mostly April–May across the U.S.

Native to Arizona

Desert ironwood is a flowering plant that USDA PLANTS lists as native in the lower 48 states. In Arizona it's most often seen in bloom in April–May.

2states where USDA records it

5,227AZ sightings*

7,466U.S. sightings*

*iNaturalist research-grade observations, as of October 17, 2026.

On our lists for: Arizona

Quick look

Olneya tesota is a perennial flowering tree of the family Fabaceae, legumes, which is commonly known as ironwood, desert ironwood, or palo fierro in Spanish. It is the only species in the monotypic genus Olneya. This tree is part of the western Sonoran Desert in Mexico and United States.
From Wikipedia's article Olneya, CC BY-SA 4.0.

It belongs to the Fabaceae family. ^iNaturalist
USDA PLANTS describes it as a shrub / a tree with a perennial life cycle. ^{USDA PLANTS}
USDA PLANTS lists it as native in the lower 48 states and records it in 2 states. ^{USDA PLANTS}
NatureServe lists it as native to Arizona. ^NatureServe
In Arizona, most iNaturalist sightings of it in flower come in April–May. ^iNaturalist
USDA PLANTS lists its flower color as purple. ^{USDA PLANTS}
USDA PLANTS gives its bloom period as early spring. ^{USDA PLANTS}
USDA PLANTS lists a mature height of about 25 ft. ^{USDA PLANTS}
iNaturalist has 5,227 research-grade sightings of it in Arizona, ranking #16 among the 132 flowers on our Arizona list. ^iNaturalist

When does it bloom?

In Arizona, most flowering sightings come in April–May.

Flowering records by month in Arizona (iNaturalist research-grade observations marked “Flowering”) (120 records)

Conservation status

Federal (U.S. ESA): Not listed No U.S. Endangered Species Act listing in the USFWS ECOS database. ^{USFWS ECOS}
NatureServe global: G4 Apparently secure worldwide. ^NatureServe
Arizona: Salvage restricted On Arizona Native Plant Law protected plants (Ariz. Admin. Code R3-3 Art. 11, App. A, eff. Feb. 2, 2025): salvage restricted (permit needed to remove). NatureServe: S4, apparently secure in Arizona. ^{AAC R3-3 App. A}
Rare elsewhere: No other U.S. state ranks it S1, S2, SH or SX.

Checked October 17, 2026. Rankings and lists can change, so follow the links for the latest.

Please leave it where it grows

Please don't pick or dig this flower: it's on Arizona's rare plant list (salvage restricted). ^{AAC R3-3 App. A}

Can you eat it?

For peopleNot well documented

None of the sources we checked (NC State Extension (no page for this plant), USDA PLANTS) say whether it's edible or poisonous for people.

For petsNot well documented

It isn't on the ASPCA plant list.

🌿 Never eat a wild plant unless you're certain of its ID; this isn't medical advice. Worried about a person? Call Poison Control at 1-800-222-1222. Worried about a pet? Call your vet.

Where does it grow?

USDA PLANTS records desert ironwood in 2 states.

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recorded by USDA PLANTS on our state lists not recorded

See the full list of states

Arizona, California.

Arizona counties with USDA records: La Paz, Maricopa, Mohave, Pima, Pinal, Yuma.

Growing conditions

USDA PLANTS gives Desert ironwood a high shade tolerance, high drought tolerance and low moisture use. It is rated for soil pH 6.8 to 8.6 and winter lows down to 22 °F.

Shade tolerance: High
Drought tolerance: High
Moisture use: Low
Soil textures it is adapted to: coarse, medium, fine
Soil pH range: 6.8 to 8.6
Minimum temperature tolerated: 22 °F
Frost-free days needed (minimum): 365
Annual precipitation range: 3 to 20 inches
Minimum root depth: 12 inches
Salinity tolerance: Low
Fertility requirement: Low
Growth rate: Slow
Lifespan: Long
Active growth period: Spring, Summer, Fall
Fruit or seed: Brown · Summer to Fall
Can be propagated by: bare root, container, seed
Commercial availability: Field Collections Only

From the USDA PLANTS characteristics data for OLTE. USDA ratings are general guidance for the species, not a guarantee for your garden.

Names, range and relatives

County records: USDA PLANTS lists it in 10 counties across 2 states; the most are in Arizona (6), California (4).

More from the Fabaceae family (114 on Bloomipedia; most observed first): Lupines, White clover, Red clover, Eastern redbud, Purple crownvetch, Bird's-foot trefoil, Partridge pea, White sweetclover.

More Arizona flowers

Little-leaved palo verde

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Velvet mesquite

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Coulter's lupine

Lupinus sparsiflorus

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Sources

USDA, NRCS. PLANTS Database, profile OLTE.
iNaturalist, Olneya tesota: taxonomy, research-grade observation counts and “Flowering” annotations, retrieved October 17, 2026.
Wikipedia, Olneya (lead quoted under CC BY-SA 4.0).
Arizona: Arizona Native Plant Law protected plants (Ariz. Admin. Code R3-3 Art. 11, App. A, eff. Feb. 2, 2025).
Arizona: Arizona prohibited noxious weeds (Ariz. Admin. Code R3-4-245).
USFWS, ECOS species database (ESA listing check), October 17, 2026.
NatureServe Explorer, Olneya tesota (global and state ranks).
Edibility and toxicity: no source found (marked "not well documented").
Photo: Cactus Kelly via iNaturalist · CC BY 4.0 · resized.