Description

Leaves: Alternate; twice (sometimes three to four times) pinnately compound; pinnae (the smallest branches of the leaf that hold the leaflets) each with 12 to 30 small leaflets; deciduous; leaflets linear to oblong, 1/2" to 2" long, margins entire, glabrous; petiole tipped with a spine; no notable fall color.

Twigs/buds: Twigs glabrous; smooth; with 1/2" to 2" long spines at each leaf.  No terminal bud; lateral buds small, round, brown.

Flowers/fruit: Flowers perfect, yellow, fragrant, small; appear throughout the summer.  Fruit a thin, flat to round legume; yellowish; 4" to 9" long and 1/4" to 1/2" wide; constricted between 1/4" long, brown seeds; edible.

Bark: Thick; dark red to brown; scaly and furrowed.

Wood: Very hard, heavy; used for lumber, firewood; heartwood brown, sapwood yellow; ring-porous.

General: Native throughout much of the southwestern U.S. south into Mexico, including extreme southwest Utah.  This shrub to small tree is well adapted to desert sites with a deep, extensive root system.  It tolerates heat, drought, high soil pH, and salinity and is quite long-lived.  Shade intolerant.

Landscape Use: This tough tree is seldom planted and likely is not very cold hardy, but it could be used in natural landscapes in Washington County.  Zones 7(?)-10.

Comments & Limitations:  Fruit and/or plant part can be nuisances; use fruitless varieties if possible.  Thorns or spines that can be dangerous; use thornless varieties if possible.

Characteristics