Ecological Groups of Stems 



163 



ish oak bark provides the 

 cork of commerce. 



The stem of the rattan 

 palm, which is one of the 

 very longest of tropical 

 climbers, furnishes the cane 

 for chairs and materials for 

 basketry and wicker furni- 

 ture. In this country 

 baskets and furniture are 

 made from shoots of the 

 osier willows. 



Stem vegetables of im- 

 portance as food for human 

 beings include the potato, 

 Jerusalem artichoke, as- 

 paragus, dasheen, and 

 kohl-rabi. 



Sorghum and sugar cane 

 furnish a considerable part 

 of the sugar and sirup of commerce 

 source of a delightfully flavored sugar. 



The crude rubber used in the manufacture of shoes, gar- 

 ments, and tires is furnished by the stem of the desert plant, 

 guayule, and the sap of various tropical rubber trees. ]\Iany 

 substances used in medicine are derived from stems directly 

 or by distillation. Wintergreen oil may be obtained from the 

 twigs of the sweet birch, and camphor from the stem and 

 branches of the camphor tree. 



The bast fibers of flax, jute, and hemp furnish material for 

 the manufacture of linen, cordage, coarse fabrics, and rugs. 



Bureau of Agricullurt, P. I. 

 Fig. 93. Tapping para rubber trees, in the 

 Malay States, to obtain the milky juice from 

 which crude rubber is made. 



The maple is the 



