RETAMA AND COLOCYNTH 



a knot in a halfa leaf, which, according to them, cures a 

 strain of the back. The Stipa is also used as fodder, but it 

 is not nutritious and is indeed sometimes dangerous. In one 

 year Britain imported 187,000 tons of esparto, worth nearly 

 £800,000. The yield is said to be about ten tons per acre. 



Another very interesting plant at Tripoli and in the North 

 African Desert generally, is a sort of broom, the Retama 

 {Retama Raetam). It is not very unlike the common broom, 

 but has long, leafless, whip-like branches covered by bright 

 pink-and-white flowers. It can often be seen half submerged 

 in waves of sand, and struggling nevertheless to hold its 

 own. As it has no leaves its loss of water is very much kept 

 down. This is the Juniper of the Bible, and it is still used 

 for making coals. 



The length of the roots is very great in most of the 

 broom-like, "hedgehog," and other plants. A quite small 

 plant not more than six or eight inches high will have a root 

 as thick as one's thumb. Even at a depth of four or five 

 feet below the surface its root will be as thick as the little 

 finger, so that the root-length is at least twenty times the 

 height of the visible part above ground. These thirsty 

 roots explore the ground in every direction, and go very deep 

 downwards in their search for water. 



Another very interesting plant in the Egyptian Desert is 

 Citrullus Coloci/nth, from which the drug colocynth is pre- 

 pared. The great round yellow-green fruit and finely divided 

 bright green leaves may be seen lying on the sand. It 

 remains green all the summer, but appears not to have any 

 particular protection against loss of water. It is always 

 supplied by its roots with underground water. If a stem is 

 cut through it withers away in a few minutes. This is 

 found also in Asia Minor, Greece, and Spain. The pulp of 



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