GEOGRAPHICAL DISTRIBUTION OF PLANTS. | 535 
an important trade since its conquest by France. On this subject 
M. Cosson, a traveller and botanist, thus expresses himself :— 
“The natural region of Northern Africa is especially characterised 
by the extreme rarity of rains, the dryness of the atmosphere and 
the extremes of temperature ; the absence of great ranges of moun- 
tains and of permanent water-courses give an aspect quite special 
to this desert-like vegetation. The number of vegetable species 
growing spontaneously does not exceed five hundred. The greater 
number of these are perennials, which grow in tufts, and have a 
dry and sterile aspect, giving them a rugged and hard appearance, 
which is quite characteristic. The families represented in the 
Algerian Sahara in greatest number are the Compositex, the 
Graminex, the Leguminosex, the Crucifere, and the Solanacez. 
Among the Ligneous species are the Tamarix, a genus of elegant 
flowering shrubs, and the Mastive-tree (Pulmia Atlantica). The 
Date-tree is, however, the chief source of wealth in the gardens of 
the Oasis. This tree is cultivated not alone for the abundance and 
variety of its products, but also for its shade, which secures other 
cultivated plants from the violence of the winds, and maintains 
in the soil the moisture required for the cultivation of other 
crops. 
** Besides the Date, the Oasis generally presents an abundant 
crop of Figs. Pomegranates, Apricots, and frequently the Vine; the 
- Peach, the Quince, the Pear, and the Apple, are invariably planted 
in the gardens of the Ksours, and in the Oasis situated near the 
hills. More rarely we meet in the Oasis, the Orange-tree, Olives, 
Barley, and more rarely still, Wheat, which is cultivated in the 
irrigated lands of the neighbourhood in the intervals between the 
Date plantations. Onions, Beans, Carrots, Rape, and Cabbages, 
occupy a large place among the plants cultivated. Pimento is 
also largely cultivated for the stimulating properties of its fruit, 
which render it a favourite condiment with the Arabs. The 
Egg plant, or Mad Apple, and the Love Apple (Lycopersicum 
esculentum), are cultivated in some gardens for their fruit. Num- 
berless species of Cucurbitacee are also sown in the gardens in 
summer, and sometimes attain a great size. The Gombo (Hibiscus 
esculentus) is cultivated here and there for its mucilaginous fruit. 
The industrial and fodder plants are principally Hemp, repre- 
