''Vachellia constricta'', also known commonly as the whitethorn acacia, is a shrub native to

Mexico Mexico (Spanish: México), officially the United Mexican States, is a country in the southern portion of North America. It is bordered to the north by the United States; to the south and west by the Pacific Ocean; to the southeast by Guatema ...

and the Southwestern United States, with a disjunct eastern population in

Virginia Virginia, officially the Commonwealth of Virginia, is a state in the Mid-Atlantic and Southeastern regions of the United States, between the Atlantic Coast and the Appalachian Mountains. The geography and climate of the Commonwealth ar ...

and

Maryland Maryland ( ) is a state in the Mid-Atlantic region of the United States. It shares borders with Virginia, West Virginia, and the District of Columbia to its south and west; Pennsylvania to its north; and Delaware and the Atlantic Ocean to ...

.USDA FEIS data
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Distribution

In the Southwest ''V. constricta'' grows in the southern half of

Arizona Arizona ( ; nv, Hoozdo Hahoodzo ; ood, Alĭ ṣonak ) is a state in the Southwestern United States. It is the 6th largest and the 14th most populous of the 50 states. Its capital and largest city is Phoenix. Arizona is part of the Fou ...

, extending into

New Mexico ) , population_demonym = New Mexican ( es, Neomexicano, Neomejicano, Nuevo Mexicano) , seat = Santa Fe , LargestCity = Albuquerque , LargestMetro = Tiguex , OfficialLang = None , Languages = English, Spanish ( New Mexican), Navajo, Ke ...

and

West Texas West Texas is a loosely defined region in the U.S. state of Texas, generally encompassing the arid and semiarid lands west of a line drawn between the cities of Wichita Falls, Abilene, and Del Rio. No consensus exists on the boundary betwee ...

. It grows in Mexico as far south as

Oaxaca Oaxaca ( , also , , from nci, Huāxyacac ), officially the Free and Sovereign State of Oaxaca ( es, Estado Libre y Soberano de Oaxaca), is one of the 32 states that compose the political divisions of Mexico, Federative Entities of Mexico. It is ...

, with small disjunct populations in

Baja California Baja California (; 'Lower California'), officially the Free and Sovereign State of Baja California ( es, Estado Libre y Soberano de Baja California), is a state in Mexico. It is the northernmost and westernmost of the 32 federal entities of Mex ...

and in the Magdalena Plain of Baja California Sur. In the

Sonoran Desert The Sonoran Desert ( es, Desierto de Sonora) is a desert in North America and ecoregion that covers the northwestern Mexican states of Sonora, Baja California, and Baja California Sur, as well as part of the southwestern United States (in Ariz ...

, ''Vachellia constricta'' grows in arroyos and washes, where it blooms in late spring (April–May), with a second round of blooms in July–October. Blooming requires a minimum amount of rain, followed by a period of warmth.

Description

''Vachellia constricta'' typically grows to in height, occasionally reaching . 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 Pinnation (also called pennation) is the arrangement of feather-like or multi-divided features arising from both sides of a common axis. Pinnation occurs in biological morphology, in crystals, such as some forms of ice or metal crystals, and in ...

, usually 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 flowers offer no nectar and little pollen, and so tend to have few visitors. Extrafloral nectaries grow along the main stem of the compound leaves and attract ants to the trees. The seed pods are relatively long and thin, up to 12 cm long but only 3–6 mm wide. The leaves may drop in response to either dryness or cold. Image:Acacia constricta pods.jpg, ''Vachellia constricta'' seed pods Image:Acacia constricta WPC.jpg, ''Vachellia constricta'' tree.

Varieties

Cultivation

''Vachellia constricta'' is cultivated by specialty

plant nurseries A nursery is a place where plants are propagated and grown to a desired size. Mostly the plants concerned are for gardening, forestry or conservation biology, rather than agriculture. They include retail nurseries, which sell to the general p ...

as an

ornamental plant Ornamental plants or garden plants are plants that are primarily grown for their beauty but also for qualities such as scent or how they shape physical space. Many flowering plants and garden varieties tend to be specially bred cultivars that ...

. It is used in

native plant In biogeography, a native species is indigenous to a given region or ecosystem if its presence in that region is the result of only local natural evolution (though often popularised as "with no human intervention") during history. The term is equ ...

desert habitat gardens. It can be trained as a small tree or grown as a barrier hedges.

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

USDA Plants profile: ''Vachellia constricta'' (as ''Acacia constricta'')

Lady Bird Johnson Wildflower Center
{{Taxonbar, from=Q4670902 constricta Flora of the South-Central United States Flora of the Southwestern United States Flora of Mexico Flora of the Sonoran Deserts North American desert flora Flora of Virginia Flora without expected TNC conservation status