LAGHOUAT. 25 



out the date a continuous occupancy of a remote oasis by the Arab is 

 clearly impossible. Besides the date palm fruit trees of other kinds are 

 abundant, among them the apricot, fig, mulberry, peach, pear, and orange. 

 The pomegranate and the table grape are also very generally grown. The 

 lowest story of the vegetation of the gardens is composed of garden vege- 

 tables, such as artichoke, bean, carrot, melon, pea, potato, squash, and 

 radish. Among the ornamentals one sees roses, asters, and chrysanthe- 

 mums, and occasionally very luxuriant cannas. One or two parks contain 

 interesting introduced trees and shrubs. We recognized among the trees 

 Ailanthus, Eucalyptus, umbrella, plane, poplar, pine, cypress, ash, locust, 

 willow, and St, John's tree. The Barbary fig {Opuntia ficus indica) is also 

 common, but does not stray away from the best-watered situations. 



THE PLAIN. 



The part of the plain (hamada) studied lies to the west of the oasis, 

 between it and the adjacent hills. Mountains of the Nomads, w^hich are to 

 the west of the pass of the Oued Mzi. Emerging from the oasis, one finds 

 himself on the arid plain, the transition from the one to the other being 

 abrupt. The plain, at first view, with a covering of small stones and pebbles, 

 gives the impression of total barrenness. Not a tree, shrub, or herb ap- 

 pears to hide the bare ground. The mountains are naked rock, while the 

 harsh outline of desert ranges and the distant low sand ridges give no evi- 

 dence of plant Hfe. But a closer examination of plain, dune, and mountains 

 reveals the presence either of living forms or of the dried remains of plants 

 of a preceding moist season, in numbers and in kinds not at first suspected. 



Close to the oasis the plain forms the highway for caravans as well as 

 the drilling ground for army recruits, so that the herbage is either trodden 

 under foot or eaten to the roots. Somewhat farther away, where the plain 

 rises to meet the mountains, we first encounter perennials large enough 

 and abundant enough for consideration, the most prominent being quedad 

 {Acanthyllis tragacanthoides) , adhidh (Zollikofena spinosa), rempt (Haloxy- 

 lon articulatum) , and drinn {Artistida pungens); Acanthyllis is perhaps the 

 m.ost numerous. 



Quedad is the most striking plant native to Laghouat. It is a shrub, 

 related to Astragalus, usually not over 40 cm. high. A single specimen 

 consists of a group of unbranched or little-branched stems, rather stout, 

 of a grayish-green color, and provided with long and stout spines. As a 

 whole the plant has a very close resemblance to small specimens of ocotillo 

 {Fouquieria splendens) of the southwestern United States. During dry 

 seasons the stems are bare, but when the rains return leaves are put out 

 in the axils of the spines, which are the rachides of the leaves. The habit of 

 quedad is shown in figs. 4 and 6. Although the species is so well protected 

 against attack by animals that it rarely, if ever, suffers on that account, 

 it is made a supplemental food through the burning off of the spines. When 

 thus prepared the half-woody stems are eaten with a\ddity by camels. 



