"العراق والخليج الفارسي" [و‎‎١‎٣‎٥] (٨٦٢/٢٧٤)

VEGETATION 187
bushes of Zilla spinosa, a thorny almost leafless much-branched shrub
belonging to the cabbage family, while one of the almonds, Amygdalus
arabicus, was seen in the deeper ravines as ‘bright green bushes’.
One of the daisy family, the yellow-flowered Asteriscus graveolens, a
low shrub with hard grey-velvety branches, was also noted in ravines.
Most of the persistent perennials in the desert are low bushy shrubs
or sub-shrubs, much-branched and compact, and rarely exceeding
2 feet high. They are widely dispersed, taking advantage always of
the slightest depression. The summer aspect of this vegetation is
monotonous and drab, the result of arid conditions. Xerophytism
is strongly marked, the prevailing grey colour of the plants being due
to a protective investiture of dense hairs which covers the entire stem
and leaf surfaces of most of the species. A few, such as the joint-
pine {Ephedra alata), lose their leaves very early or reduce them
much in size. Others are rough and prickly, with an impermeable
surface of tough cuticle, coupled often with a hairy covering as well.
Arid soils are usually peculiar for their high content of mineral
salts. This fact accounts for the presence in the desert of a number of
maritime species belonging mostly to the goosefoot family (Cheno-
podiaceae). Many plant communities covering large areas are domi
nated by species belonging to this group. Characteristic of the stony
lands of the Hamad, for example, is Haloxylon articidatum, a low
shrubby plant with jointed stems and scale-like leaves. Another
species, H. salicornicum, a low herbaceous fleshy plant, prefers sandy
soils and occupies large tracts from Basra to Ur. A third species, also
restricted to sandy soils, is H. persicum, a tree-like shrub up to 20 feet
in height, with white bark and brittle branches. It somewhat re
sembles tamarisk and is a most useful desert plant, supplying the
beduin with camel-fodder, timber, and fuel. The sandy or sand-
gravel soils of the Zubair desert south of Basra are dominated by
Rhanterium epapposum, a low branching shrub belonging to the daisy
family. Known to the beduin as arfaj, it also is useful both as fuel and
fodder. Other representative perennials in this area are the spiny
milk-vetch {Astragalus spinosus), a low hairy spinous shrub; a sun
rose {Helianthemum sessiliflorum) with yellow flowers and whitish
branches; two relatives of mignonette, Reseda decursiva and R. ara-
bica ; and a stork’s bill {Erodium glaucophyllum) with prostrate stems,
grey hairy foliage, purple flowers, and fruits with beaks up to 3 inches
long. The summer aspect of this desert, however, is poor, since two-
thirds of the total flora consist of annuals which disappear in the dry
season.