I.] 



APOCYNACE^E. 



187 



tropical species of the Family abound in a milky juice, 

 which is collected for the sake of its caoutchouc. 



Closely allied to Apocynaceae is the exotic Asclepias 

 Family, including the beautiful Hoyas and Stephanotus 

 of our stoves and the Carrion-flowers (Stapelias) of South 

 Africa. The pollen of Asclepiads .is held together by a 

 wax-like cement, so as to form pollinia resembling those 

 of Orchids. 



43. Natural Order Gentianaceae. The Gentian 

 Family. 



DISTRIBUTION. Widely spread in both hemispheres ; 

 most numerous in temperate and alpine regions. British 

 genera 6, species n. 



Herbs. Corolla hypogynous, regular, lobes twisted in bud. 



Stamens alternate with corolla -lobes. Ovary usually 



I -celled, with parietal placentas. 



Type Autumn Gentian (Gentiana Amarella). 

 A small erect smooth annual, with opposite entire 

 leaves, and numerous purplish flowers. 



OBSERVE the connate leaves of Yellow-wort (Chlora 

 perfoliatd) : trifoliolate leaves and bearded petals of 

 Buckbean {Menyanthes trifoliata) : orbicular floating 

 leaves of Fringed Buckbean (Limnanthemum nym- 

 phce aides). 



