258 SOUTH AFRICAN FLOWERING PLANTS, 



that is, they grow " upon plants," mostly trees— but 

 they are not parasites, for they derive no nourishment 

 from their supports. They are provided with long, 

 aerial roots, by means of which they fasten themselves 

 to the branch of the tree, and also absorb water, etc., 

 from the surface. Fig. 99 illustrates one species of 

 an epiphytic orchid of South Africa, from the Eastern 

 forests, known as Mystadd'ium grac'ile. 



Angrge'cum. — This is another epiphytal genus. 

 Species are found both on the east and west sides of 

 South Africa, as well as Madagascar, where A. sesqui- 

 peda'le occurs, having a long slender spear, sometimes 

 reaching about fourteen inches in length. The sepals 

 and petals are nearly equal, spreading and free; the 

 flowers are mostly white. 



General Description of the Orchid Family. 



Eerhs — Terrestrial or epiphytal. 



Ze<xt;es— Simple, entire, sheathing, forming pseudo- 

 hulls, or thickened internodes, if epiphytal. 



Flov:ers — Perianth irregular, superior; stamens, 1 

 or 2 {Cyioripc'dium) ; pollen, coherent in masses, with 

 viscid disk or ; stigmas, 2, effective, 3rd, a rostellum ; 

 ovary, inferior, 1 -celled, with 3 parietal placentas. 



j^^^^^_ Capsule, bursting by valves, rarely succulent 

 ( Vanil'la). 



