Fig. 83. Annuals growing with Peganum, near Biskra.
Fig. 84. General view of the north face of the Djebel Bou Rhezal, Biskra. Apparently barren, plants are rather numerous in the rock crevices and small washes of the mountains.
FOOTNOTES:
[1]Kearney and Means, Agricultural explorations in Algeria, Bul. No. 80, Bur. Plant Ind., U. S. Dept. Agric., 1905.
[2]A. Engler, Die Vegetation der Erde IX. Die Pflanzenwelt Afrikas. 1 Bd., 1910, page 902.
[3]The seasonal distribution of rain (by percentages) is somewhat different from that given by Engler, which is given in the accompanying table.
| Season. | Littoral. | Tell. | High plateau. |
|---|---|---|---|
| Winter | 41 | 36 | 45 |
| Spring | 27 | 32 | 46 |
| Summer | 4 | 7 | 11 |
[4]The most recent records available, 1897-1908, do not give a satisfactory account of the precipitation on the desert. For instance, meteorological records covering eight years for El Golea do not report on the rainfall. Records of five years at In Salah take the rainfall into account on one year only, and on that year no precipitation occurred.