“The plain
Which from its bed rejecteth every plant;”
whose soil is—
“Of an arid and thick sand;”
and where—
“With a gradual fall
Are raining down dilated flakes of fire.
As of the snow on Alp, without a wind.”[66]
CHAPTER V.
VEGETABLE LIFE IN THE DESERT:—THE OASES.
THE Flora of a region where nature provides no genial fertilizing rains, and whose soil is simply a shifting sand, moistened only in certain places by a brackish water, must necessarily be one of extreme poverty.
It is reduced very nearly, as we have seen, to a few plants of the genus Salsola (salt-wort), flourishing on the borders of the salt pools and lakes. Nevertheless, at a few points, where a certain degree of fixity obtains in the sand, we meet with the thornless bushes or shrubs, the Ephedra alata and the retama Duriœi; some pistachios (pistacia lentiscus and p. terebinthus); the “drin” (aristida pungens), a tall grass, with linear leaves, some seven feet high, to which the camel is very partial; and the “ézel,” a member of the family of Polygonaceæ, which botanists class with the allied buckwheat and knot-grasses, and which attains the stature of three to four feet. The latter plant throws out roots, which are generally uncovered, to a distance of twenty to twenty-five feet; its woody stem spreads in its upper portion into gnarled branches, terminated each by a cluster of green, cylindrical and leafless twigs, which fall during winter. Elsewhere rise the tall trunks of the doum-palms, either isolated or assembled in scanty clumps, under which the traveller obtains with difficulty a modicum of shade, but which are otherwise of no value to him.
In districts where the surface is more broken up, notably in Palestine, on the banks of the Jordan and the Dead Sea; in the Sinaitic Peninsula of Arabia; in the Nubian deserts of Naga, Aredah, and Bahiouda; finally, even in the Sahara, in the “Desert of Erosion,” and the table-land region, vegetable life becomes more abundant and more varied, though still but of mediocre interest. However, a curious arbustus, the Limioniastrum Guyonianum, shows itself very frequently in these damp localities, where it attains sometimes the dimensions of a tree. Its attenuated leaves are covered with saline efflorescence, and its particles of rosy flowers relieve the monotony of the wilderness. In the permanent salt marshes, or chotts, some of the plants are analagous to those formed in the bogs of Languedoc.