CLASSIFICATION OF ANGIOSPERMS. 



497 



is a pod or capsule, which dehisces mostly by means of 6 valves, 

 and contains numerous minute seeds, which are without endo- 

 sperm, and the embryo of which lacks frequently any trace of 

 external organs. The seed-coat is membranous and loose. 



FlG. 274. A fruiting plant of Vanilla planifolia, an epiphytic orchid, which is indige- 

 nous to Mexico and extensively cultivated in tropical countries, especially in Mexico and 

 Java. The photograph is of a plant growing in Dominica, an island of the West Indies, 

 and shows the long, elliptical leaves, also some of the long, slightly curved, slender pods. 

 The latter are not fragrant, but develop their characteristic aroma by a process of slow 

 curing. Reproduced by permission of The Philadelphia Commercial Museum. 



Vanilla planifolia, which yields the official vanilla, is a high- 

 dimbing plant with long internodes and distinct nodes from which 

 arise more or less oval or broadly lanceolate, somewhat fleshy 

 leaves and also commonly a single aerial root. The long stem 

 is terminated by a raceme, flowers also arising in the axils of the 

 32 



