1828 



A TEXTBOOK OF THEORETICAL BOTANY 



Geranium (Fig. 1731), of which there are about 300 species, covers the widest 

 range. G. pratense, G. syhaticum, and G. robertiamim extend into the Arctic, 

 while G. patagoniaim and G. magellanicum are found within the Antarctic. 

 Eleven species of this genus occur wild in Britain. 



Fig. 1731. — Geranium pratense. Longitudinal section of flower. 

 {After James and Clapham.) 



The genus Erodiiim is also a large one, with about sixty-five species, of 

 which three are found in Britain. The genus Pelargonium with about 

 250 species is found mainly in South Africa. 



The genera of the Geraniaceae fall naturally into five sub-families. 



I. Geranioideae 



Ovary beaked, sepals free, imbricated. Ovary containing one or rarely 

 two ovules in the loculus. Geranium, Erodium, Pelargonium, Monsonia, 

 Sarcocaulon. 



II. Biebersteinioideae 



Ovary not beaked, sepals free, imbricated, ovary containing a single 

 eed. Biebersteinia, native of central and western Asia. 



III. Wendtioideae 



Ovary not beaked, sepals free, imbricated, ovary containing two to many 

 seeds. Rhynchotheca, Wendtia, Balbasia, occurring mainly in South 

 America. 



IV. Vivianoideae 



Ovary not beaked, calyx tubular, fruit a capsule. Viviania, found in the 

 Andes. 



