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General Botany 



without even holdfast roots. It is an extreme xerophyte, living 

 not only in the moist sub tropics but some species occurring even 

 in semi-desert regions. 



The orchid family (Orchidaceae) . The orchids form the 

 culminating family of the monocots. They are all perennial 

 herbs, noted for their beautiful, highly specialized and diversi- 

 fied flowers. In temperate regions the species are mostly ter- 

 restrial, but in the tropics they are largely epiphytes. During 

 the dry season they drop their leaves, and only the thickened 

 stems, tubers, or fleshy roots pass the dormant period. The 

 fruit is a capsule containing a vast number of minute seeds. In 

 many of the tropical epiphytes the outer layers of the root con- 

 sist of dead perforated cells, which form a water-holding tissue 



(the velamen). The great vari- 

 ety of orchids is indicated by the 

 occurrence of 750 genera and 

 7500 species. 



Other monocot families. The 

 banana family includes many 

 gigantic herbs of the tropics, 

 noted not only for their fruit, 

 but in some species for the fibers 

 obtained from their leaf stalks 

 (Manila fiber). 



The yam family includes 

 many climbing herbaceous 

 plants, with thick underground 

 tubers that in tropical countries 

 are eaten like potatoes. The 

 leaves of this family resemble 

 those of dicots. 



To the monocots also belong 

 many of the families which in- 



FiG. ^^S- A tropicsd orchid {Cypripedium „4-^^ 



caiiosum). cludc our commoucst water 



