Thursday, July 5, 2012

Parkinsonia aculeata........Jerusalem Thorn

 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.