ot Rem 
= — Botanical Geography, spe 443 
‘remain in the fruits attached to the branches, and thus, 
like the banyan, can produce a group of trees from a single 
individual ; laurels, teak-trees, lanes, numerous beautiful 
Orchidez, Nepenthacez, and Nymphzacez. The most 
important food-plant is rice. Cotton, the opium-poppy, 
ginger, sesame, and indigo are also widely cultivated crops. 
Among fruit trees and useful shrubs, the coffee-plant is 
grown in Java, cinnamon in Ceylon, the nutmeg and clove 
in the Moluccas; the bread-fruit and the cocoa-nut- -palm 
~ in the South dea Islands, camphor in Borneo, pepper in — 
Malabar and Siam. In addition the plantain, cena and | 
other sweet fruits are universal. 
7. The Sahara. 
This is the region of the unchecked prevalence of the 
trade-winds in northern Africa, northern Arabia, and southern. 
India, and is almost rainless. Any vegetation is possible 
only from the occasional occurrence of thunderstorms or 
dew, or from the rainfall of adjoining regions being carried 
underground as surface-water, and giving rise to springs or 
wells. But it is scarcely conceivable that there are even in the 
Sahara any large tracts in which a scanty vegetation cannot 
thrive at certain times. The nature of the surface indicates © 
four varieties of landscape :—the stony plains of the Ham- 
mada ; the undulating deserts of the Areg covered with shift- CD 
-. ing sand ; the deep gullies or Wadis ; and the Oases. The 
Hammada brings forth only at particular spots scanty thorny 
or leafless shrubs, and sometimes also saline plants. The 
Areg sometimes produces Grasses. The rest of the scanty 
vegetation of the desert, oily and bulbous plants, &c., retreats | 
to the Wadis and the Oases with their date-palms. The 
date-palm is the only tree which has its original and uncon- » 
_ tested home in the Sahara ; the rest, as well as a number of 
other plants, have migrated Pee elsewhere or been introduced 
by man. 
