288 



MANUAL OF BOTANY 



them. This is supposed to be the case more j)articularly with 

 Vaccaria vulgaris. Saponaria officinalis has been used in 

 syphihs ; it contains a pecuhar principle called saponin. This 

 principle has also been found in species of Lychnis, Silene, 

 Ciicuhalus ; and more esj^ecially in Gijpsojihila Stvuihium, to 

 which latter plant it communicates well-marked saponaceous 

 properties : hence it is commonly termed Egyptian Soap-root. 

 The other species in which saponin is found also possess, to 



Fig. 1057. 



Fig. 1060. 



Fig. 1061. 



Fig. 1057. Diagram of the flower of a species of Dianthitii. Fig. 1058. Ver- 

 tical section" of the flower of the same. — Fig. 1059. Sporophylls of a 



species of .SVr//,7/vV/. Fig. Iu60. Capsule of a species of ZJ/mi^/i/i.?, dehiscing 



partially in a valvular manner so as to form four teeth at the ape.v. 



Fig. lOGl. Vertical section of the seel of L'hiekweed {Stellar ia media).] 



some extent, similar properties. Saponin is reputed to be 

 poisonous in its nature. 



Some of the plants have show^^ flowers, as the species of 

 Dianthus, Silene, and Lychnis; but they are generally insig- 

 nificant weeds. Dianthus harhatus is the Sweet- William of our 

 gardens ; D. plumarius is the parent of all the cultivated 

 varieties of the common Pink ; and D. Caryophyllus, the Clove 

 Pink, is the origin of the Carnation and its cultivated varieties, 



