BOTANICAL APHORISMS. 18] 
§ 173. 
‘The sex, (sexus), of plants, can never serve as @ 
discriminating character of a genus. 
{f a plant differs from another in sex, this circum- 
stance Is not to be taken into the generic character ; 
at least it cannot serve any important purpose. We 
have already remarked, that no character is more 
unsteady than that of sex ; for hermaphrodite flowers 
are often by culture changed into male and female 
flowers, and even difference of climate produces the 
same effect. For instance, in our garden, the Cera- 
tonia siliqua is constantly observed with perfect 
flowers, of different sexes on different trees, (Dioe- 
cia), though in Egypt it is constantly found with 
hermaphrodite flowers. Many genera, as Lychnis, 
Valeriana, Cucubalus, Urtica, Carex, &c, have 
species with hermaphrodite flowers, though all the 
rest are dioicous. 
Flowers that are of neither sex, (/lores neutri), 
having neither stamina nor style, and which are 
found between fertile flowers, as in Viburnum and 
Hydrangea, cannot serve as generic marks. ‘The 
plants of the 19th class form the only exception. 
Hitherto we have only stated the rules that are 
generally applicable, to all the families of the ve- 
getable kingdom. ‘There are, however, particu- 
far rules for single plants that we must here take 
notice of. Whoever attends to them and to the 
rules already laid down, will find no difficulty in 
characterizing genera. Particular rules might be 
dee ast CLV Cg, 
