SEED-BEARING PLANTS 



497 



The roughness of the surface is caused by the persistence 

 of the styles and the fleshy sepals. 



The family is divided into several sub-families on the 

 basis of various structural differences, such as phyllotaxy, 

 venation of leaves, presence or absence of milky juice, 

 presence or absence of perianth, and others. 



Fig. 381. — Cocoanut palms along the beach. Philippine Islands. 

 (Photo from Bureau of Science, Manila.) 



432. Orchid Family (Orchidaceae). — The Orchidaceae 

 are the most highly developed of all monocotyledons. 

 No flower surpasses the orchids in beauty of color- 

 pattern, endless diversity of unusual forms, and wonder- 

 ful mechanisms that secure cross-pollination by insects. 

 As in the papilionaceous flower, the flower of orchids is 

 bilaterally symmetrical (zygomorphic), with (usually) 

 three sepals resembUng in texture the three petals (Fig. 

 32 



