CLASS XXII. DICECIA. 
(two houses.) 
This class consists of such genera, as have male and female 
flowers distinct on two separate plants. 
OBSERVATION. 
There are many plants which have male and female flowers 
distinct on two separate roots, yet are not admitted to this 
class, because they are'only species of some particular genus* 
which agree in all other instances with the generic character 
to which they belong; as valeriana, { triandria); rhamnus, 
rhus, lonicera,phylica, (pentandria); rumex, (hexandria);7«M- 
rus , (enneandria); guilandina, cucuhalis, lychnis, phytolacca, 
gypsophyla, (decandria); spiraea, rubus, (icosandria); clematis f 
lhalictrum,l polyandria); napeea, (monadelphia); gnaphalium f 
(syngenesia); carex, urtica, morns, (moncecia). 
It may also be observed, that none of the species of the 
rough-leaved plants of Ray, in class and order pentandria f 
monogynia, or in the classes didynamia, tetradynamia, and 
diadelphia', have any of the species been found to have distinct 
sexes on different plants. 
This class contains fourteen orders, 
Founded on the number, union, and situation of the stamina in the 
male flowers. _ 
ORDER I. MONANDRIA. 
(one male.) 
N° of 
Species is 
3S° Genera. 
Growth, species. Native of 
Britain, 
1 Ascarina 
h I 
% Najas 
h 1 Europe 
$ Keura 
t I 
