Acacia jennerae and A. cowleana
are two new desert-adapted Australian acacia species recently
introduced to the desert southwest. Both are relatively small in
stature and evergreen. While each has a unique appearance and
structure, both are unarmed, having no thorns, and share an open
branching habit and lacy leaf canopies.
Acacia cowleana,
which according to one reference takes its name from Trooper
Cowle, is typically found along creeks and in sandy soils but
will tolerate a range of soil types from sandy to clay. It is
widely distributed throughout the semi-arid regions of the
Northern Territories, Southern and Western Australia, where
annual rainfall averages 8 to 20 inches. Established trees can
survive extended drought. A. cowleana is fast-growing, easily
established in its native setting and matures to a height of
about 15 feet in the wild. Initial nursery evaluations in the
Southwest U.S. suggest that similar growth can be expected here.
The leaves
(or phyllodes) are 4" to 6" long by 3/4" wide, elongated, stiff,
leathery (similar to A. redolens),
curved and dull green in color. These leaves create a canopy
that is open, spreading and rounded in form. Silver-gray
branches and trunks contrast with the leaf canopy, creating a
bold contrast and giving the tree texture. Flowers, which appear
in clusters at branch tips, are rod-shaped, cream-colored, and
inconspicuous. In the nursery this tree typically flowers in
winter. Flowers are followed by flat narrow pods 2" long by 1/2"
wide. It is not commonly cultivated as an ornamental in
Australia.
Recent
interest in this species has surrounded its use in sub-Saharan
Africa as a food crop. Seeds from the tree are highly
nutritious, easily collected and are being used by villagers in
stews, pancakes and pasta.
Acacia jennerae,
Coonavittra Wattle, takes its name from the town Coonavittra in
New South Wales, Australia. The contrast between the reddish
branches and stems with the dull green leaves make this a
striking, medium stature, evergreen tree.
A. jennerae
has vertically ascending branches, with drooping tips, giving it
a vase-shaped, upright, narrow profile. With rigid, upturned
leaves the canopy is compact yet lacy giving the tree lush
texture that provides scattered shade. Yellow to gold
ball-shaped flowers, in 3-to-8-flower clusters are produced from
November to February and sometimes in response to summer
irrigations. Pods have a zig-zag appearance, gray-brown to tan
and about 4" to 7" long. Trees can reach a mature height of 20'
and width of about 12'.
