Acacia constricta

Taxobox
name = "Acacia constricta"

---

image_width = 240px
regnum = Plantae
divisio = Magnoliophyta
classis = Magnoliopsida
ordo = Fabales
familia = Fabaceae
genus = "Acacia"
species = "A. constricta"
binomial = "Acacia constricta"
binomial_authority = Benth.

"Acacia constricta", often known as the whitethorn acacia, is an acacia shrub native to Mexico and the southwestern United States.

It typically grows to 2 meters in height, occasionally reaching 3 m. Its stems range from a light gray to a mahogany color, with pairs of straight white spines anywhere from 0.5 to 2 cm long. The small leaves are even-pinnate, typically 2.5-4 cm in length, with each of the 3-9 pairs of pinnae made of 4-16 pairs of leaflets, which are about 3.5 mm long and 1 mm wide. The flowers occur in small yellow balls about 1 cm in diameter. The pods are relatively long and thin, up to 12 cm long but only 3-6 mm wide.

In the Sonoran Desert, it is usually found in arroyos and washes, where it blooms in late spring (April-May), with a second round of blooms in July-October. The bloom depends on having a minimum amount of rain, followed by a period of warmth. The flowers offer no nectar and little pollen, and so tend to have few visitors.

In Arizona, it is found throughout the southern half of the state, extending southward throughout Sonora. Small disjunct populations have been collected from Baja California and Baja California Sur, the latter from the Magdalena Plain.

The leaves may drop in response to either dryness or cold.

"A. constricta" sees some use in desert gardens; it can be trained into barriers or as a tree.

Botanical Varieties

* "Acacia constricta" var. "constricta"
* "Acacia constricta" var. "paucispina"

References

General References

* Raymond M. Turner, Janice E. Bowers, and Tony L. Burgess, "Sonoran Desert Plants: an Ecological Atlas" (Tucson: The University of Arizona Press, 1995) pp. 15-16

External links

* [http://www.fs.fed.us/database/feis/plants/shrub/acacon/all.html USFS Acacia constricta]
* [http://plants.usda.gov/java/profile?symbol=ACCO2 USDA: NRCS: Plants profile]
* [http://www.wildflower.org/plants/result.php?id_plant=ACCO2 Lady Bird Johnson Wildflower Center]