5o8 A TEXT-BOOK OF BOTANY. 



leaves ") are mixed with the Areca nut and lime and constitute 

 what is known as '' Betel," which compound is used for chewing, 

 in India and other countries, chiefly on account of its astringency. 

 The root of Piper mcthysticum is also chewed, and when mixed 

 with the milk of the Cocoanut yields an intoxicating drink which 

 is used by the inhabitants of the Sandwich Islands. The dried 

 root has been used in medicine under the name of Methysticum 

 or Kava-kava. It consists of large, branching, soft, spongy, 

 dark brown pieces, which are tough, fibrous, and with a pungent, 

 somewhat bitter taste. Kava-kava contains 3 resins, one of which 

 has marked anaesthetic properties ; an alkaloid, kavaine ; a neutral 

 body, methysticin ; and about 50 per cent, of starch. The drug is 

 free from calcium oxalate crystals, these being usually wanting 

 in the Piperacese. 



II. ORDER SALICALES. 



This order comprises but a single family, namely, the Sali- 

 CACE.E or Willow Family, to which belong the willows and pop- 

 lars. The plants are dioecious shrubs and trees ; the flowers being 

 in aments or catkins and without petals or sepals. The fruit is a 

 capsule containing many seeds which are small and with long, silky 

 hairs at the base. 



The barks of a number of the members of this group contain 

 glucosides, as salicin, which is found mSalix alba, the white willow 

 of Europe and the United States, and the brittle willow Salix fra- 

 gilis; and populin, which is found in the white or silver-leaf poplar 

 {Populus alba) of Europe, Asia, and the United States and 

 Popnlus pyramidalis of Italy. These principles are also found in 

 other species of willow and poplar. A number of the barks con- 

 tain a yellow coloring principle allied to quercitrin, as Salix dapJi- 

 noides of Europe and Salix alba. Tannin is a common constituent 

 in both the willows and poplars. The buds of many of the poplars 

 contain in addition a volatile oil which is in the nature of a di- 

 terpene, as those of Populus pyramidalis. Populus balsamifera, 

 the tacamahac or balsam poplar of the United States and Canada, 

 furnishes the balm of Gilead buds which are coated with an 

 oleo-resin that gives them their aromatic properties. Populus 



