Jerusalem
thorn is a small tree growing to 25 ft tall with a short trunk and a graceful,
spreading, crown.
The splendid specimen in the garden at Cortijo Azahar was grown from a seed some eight years ago now.
The
slender branches and twigs have green bark, and are armed with spines.
It has peculiar straplike, twice compound leaves that look like long,
feathery streamers. Each leaf is modified into 2 or 4 strips about 10-16 in long
and less than an 1 in wide.
Each strip has 22-30 pairs of tiny opposing
leaflets less than 0.33 in long.
The
leaves appear shortly after rain, they fold up at night, and usually within a
few days the tiny leaflets drop off, leaving the persistent rachises (midribs)
to flutter like streamers in the wind. Eventually these fall off too, and
accumulate like pine needles beneath the tree.
The
brown pods are about 3-4 in long and constricted between the
seeds.
A
spectacular display of clustered pealike, yellow-orange, fragrant flowers in
spring makes the whole tree look like a giant yellow bouquet.
The
genus name Parkinsonia honors the English botanist John
Parkinson (1567–1650), while the species Latin name aculeata refers
to the thorny stem of this plant. It
belongs to the Fabaceae family.
There are five species in the genus Parkinsonia: four in North and South
America and one in South Africa. Jerusalem thorn is native to desert grasslands
and canyons in Mexico and the SW US. .
It is grown as an ornamental in tropical and
subtropical climates and has escaped cultivation and established in Florida,
California, the West Indies, and in Australia where it is regarded as one of
the most troublesome invasive weeds in the Northern Territories
Jerusalem thorn has been used to revegetate
desertified regions in Africa and Pakistan.
It is highly adapted to life in the desert. It has largely done
away with leaves that lose water through evaporation and transpiration,
producing its food instead within the photosynthetic tissue of the bark.
Jerusalem Thorn is well suited to informal landscapes and looks well in a cactus and succulent garden. Its lacy foliage and slender twigs contrast with the
solid shapes of the succulents.
Unaffected by heat, it
makes a fine street or patio tree and provides a delicate, filtered shade.
Native Americans harvested the seeds of Jerusalem
thorn which they sun dried for storage and parched over dry heat before eating.
An infusion of leaves, flowers and fruits is an alternative remedy to reduce
fever, prevent malaria and ease rheumatism
The
raw and cooked seeds are rich in proteins.