690 



BOTANY 



PART II 



is united into a pollinium, the stalk of which is attached to a glandular 

 swelling (adhesive disc) of 

 the angular stigma. These 

 adhesive discs alternate with 

 the stamens so that the two 

 pollinia attached to each 

 disc belong to the halves 

 of two adjoining stamens. 

 Visiting insects remove, as 

 in the Orchidaceae, the pol- 

 linia and carry them to 

 another flower (Fig. 746). 



FIG. 741. Gentiana lutea. a and b, 

 Flower - buds (nat. size), showing 

 calyx (a) and twisted corolla (ft) ; 

 c, transverse section of ovary. 

 OFFICIAL. (After BERG and 

 SCHMIDT.) 



FIG. 742. Vinca minor ( nat. size). 



Vincetoxicum officinale (Fig. 747) is a European herb with inconspicuous white 

 flowers and hairy seeds which are borne in follicles ; poisonous. Other forms are 

 mostly tropical or sub - tropical. The succulent species of Stapelia, JToodia, 

 Trichocaulon, etc., which resemble Cactaceae in habit, and inhabit S. African 

 deserts, and Dischidia rafflesiana ( 33 ), the peculiar pitcher plant of the Malayan 

 region, the pitchers of which serve to condense water, deserve special mention. 

 Hoya carnosa is frequently cultivated. 



OFFICIAL. Hemidesmus indicus yields HEMIDESMI RADIX. 



Order 5. Tubiflorae 



Flowers pentamerous, actinomorphic, or zygomorphic. Carpels 2. 

 Ovary superior, bilocular, with two ovules, which are frequently 



