Acacia
caven (Espino Caven) is a South American native that
shares many traits with familiar, southwestern natives like
Sweet Acacia and Native Mesquite. In central South America
(Peru, northern Chile and Argentina), where it is the second
most widely distributed native tree, A. caven is called
Espino Caven, Espinillo and Amorito. It is found growing in
several forms including as a hedged shrub (3 to 6 feet tall) and
small tree (6 to 8 feet tall), but can ultimately reach a height
of 25 to 30 feet. Botanically it is closely related to Sweet
Acacia, (Acacia smallii) sharing similar growth habits,
flower color, shape, thorns and exhibiting high genetic
variability. This variability may be due in part to it’s wide
geographical distribution across a thick band of South America.
At least 6 varieties of A. caven are recognized in
South America, each tending to be geographically isolated. In
Chile’s semi-humid regions, large, nearly pure stands of Espino
are found, similar to bosques of native mesquites in southern
Arizona or southern Texas. The tree has a broad spreading growth
habit and produces fragrant fruit. Bright yellow, ball-shaped
flowers are produced in the early spring prior to the emergence
of new leaves. Flowers are densely arranged along the surface of
the branches, similar to Sonoran Palo Verde (Cercidium
praecox) or Twisted Acacia (Acacia
schaffneri). Trees can be found in native
settings growing from sea level to over 9000 feet. Trees tend to
thrive near towns and cities, invading cultivated fields and
abandoned pastures. Its potential as a substitute for Sweet
Acacia initially drew the interest of wholesale tree growers.
Its adaptability to an array of growing conditions and growth
and horticultural characteristics makes it an excellent addition
to the desert landscape palette. In tests conducted in Tucson it
tolerated temperatures of 15 degrees F with no significant
damage. Its natural growth habits strongly suggest that the tree
would be well adapted to planting in groupings to create small
bosques, as a perimeter planting or as individual specimen
trees, placed strategically to take advantage of the flower
color and fragrance.