decorticans has two common names, Chanar
and Chilean Palo Verde. Chilean Palo
Verde possibly comes from the mottled green color of
the trunks but does not seriously resemble Cercidium. It is
found in a number of semi-arid regions of Bolivia, Brazil,
Patagonia and Argentina. Chanar is found growing naturally from
sea level to over 7,000 feet where it may grow as a shrub or to
a tree nearly 30 feet tall. Trees tend to be quite upright with
a spreading canopy with both straight and mildly curving trunks.
Leaves are cold and drought deciduous. It tends to occur in
areas with high water tables or near permanent sources of water.
As trees mature
the trunks and branches take on a sculptural quality with long
longitudinal, irregular ridges and valleys. Along with this
undulating trunk, large flakes of the bark peel off or
decorticate (hence the species name decorticans). The peeling
tan to brown bark is eventually shed revealing the dark green,
"immature" trunk beneath. The contrasting colors and textures
created by this puzzle-piece pattern make the tree visually
pale yellow flowers are produced in spring, either singly or in
clusters. Geoffroea is unique among legumes in that it produces
fleshy, oval pods that hold a single seed. Fruit are initially
green but turn orange brown as they mature. Seeds and fruit are
valued as human and animal feed and the yellow wood is suitable
for carpentry and furniture making.
Cold hardy to at
least 15 degrees, the tree has grown successfully for many years
at the Boyce Thompson Arboretum (Superior, AZ)
and at the Desert Legume Program in Tucson, AZ. Leaves are small
and dispersed and pale gray green in color. Twigs are rigid,
gray green and end in a sharp thorn. Trees can spread by root
sprouts to form thickets. In wide-open areas or on the landscape
perimeter this may be a desirable quality. In more confined
settings sprout growth can be eliminated by pruning and by
avoiding over irrigating trees.
With its unique
form and sculptural trunks Chanar produces dramatic silhouettes
by day and accentuated with landscape lighting by night. It is
best used as a focal point specimen tree, at entries, with
signage or in groupings.