Common Name(s): White Thorn Acacia

Synonym(s):

Family: Fabaceae

Native To: Southern Arizona and New Mexico, west Texas, and Mexico

Native Habitat: Arroyos, washes, rocky hillsides

Growth Habit: Large multi-stemmed shrub or small single-trunked tree

Flowering: April-May, July-October

Distinguishing Characteristics: Plants of A. constricta drop their leaves during both drought and cold periods. When present, the leaves are alternate, bipinnate, 1-2 in long. The pinnae are found in 3-7 pairs per leaf, with 6-16 pairs of leaflets per pinna. There are two very small spines derived from stipules at each node. The bark is dark brown to black in color and may be smooth or slightly rough. Small, yellow flowers are in round, dense heads, characteristic of the mimosoid legumes. The heads are 1/4-1/3 in diameter. Fruiting occurs from July through September. The pods are slender, reddish brown, about 2-5 in long and up to 1/6 in wide, and are distinctively constricted between the seeds.

Natural History Notes: The species name, constricta, refers to the pronounced constrictions of the fruit between each seed. Some birds, including quail, consume the seeds. Jack rabbits eat the foliage and, when food is scarce, cattle eat the pods. Rodents gather seeds, caching and losing some, thus aiding in dispersal. Both winter and summer rains trigger flowering. Flowers are yellow and densely packed into round clusters; they are extremely sweet-scented and fill the desert air with fragrance on spring and summer nights. Both native and non-native bees use the fragrant flowers as a source of nectar, an ingredient in desert honey made by European honeybees.

Ethnobotany: Native Americans of the Southwest grind the seeds into a meal. Members of the Seri tribe make a tea from the mashed seeds and leaves to alleviate diarrhea or upset stomach. A medicinal tea may also be made from the roots. Powdered seed pods and leaves were used to treat skin rashes.

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