Acacia constricta     
Whitehorn acacia   
Fabaceae Family     

Compiled by the Master Gardeners
of the University of Arizona Pima County Cooperative Extension.


Form: large shrub or small multistemmed tree; can be trained to single stemmed tree
Seasonality: deciduous
Whitethorn acacia
shrubby form of Acacia constricta
Size: 6-20ft with equal spread; slow growth rate
Leaves: bipinnately compound; leaflets 1in long 1/2in across
Flowers: yellow puffballs, aromatic, biggest bloom in spring and early summer, then sporadic
Fruit: slender, long pods (2-5in), dark brown, pod sheath constricted between seeds
Stems/Trunks: white thorns of varying length; typically 1/4 to 1in long and white; thorns are most obvious on young trees, fewer found on mature specimens; young stem growth has reddish color
Range/Origin: Chihuahuan deserts of New Mexico and Texas, Sonoran deserts of Arizona and Mexico; elevations of 1500-5000ft
Hardiness: to single digits


puff-ball flowers
just-opening flowers


may be thornless at any age

usually multistemmed

thorns thorns
two forms of thorns on labeled specimens of Acacia constricta

comparison chart for select Acacia species
         A. greggii A. smallii A. constricta
thorns small, distinctively hooked or curvedwhite, usually on new growthstraight, white, also on new growth
leaflets oval, less numerousmuch smaller, more numerous, feathery or fernlikeferny, numerous leaflets, each leaflet smaller
stems gray dark with age, almost blacktwigs are reddish
growth rate  fastest 
growth habit tree most upright tree
origin not native 
uses barrier most commonly used in landscapes  

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This page was first created August 2, 2002 and last modified March 15, 2006.

Web page design and photographs by Toni Moore, Master Gardener
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