188 CLAsa MONCECIA. 



that of the present and following, is likewise obvious 

 from the variable number of their stamina, which would 

 render their arrangement elsewhere not only unnatural, 

 but perplexing, and almost impossible, and the genera 

 instead of being, as they now are, brought together, 

 would then be dispersed, and nearly lost in the rest of 

 the different classes of the system. 



The class being founded on the circumstance offer- 

 tile and infertile flowers on the same plant ; the orders 

 are conveniently taken from the other classes, according 

 to the number and accidents of the stamens. 



In the order Monandria, then, we now find the 

 somewhat puzzling genus Euphorbia, or Spurge, form- 

 ing the type of the natural order Euphorbiaceje, for- 

 merly arranged in Dodecandria, and then considered 

 as a simple, in place of a compound flower. They all 

 contain an acrid milky juice, that of some of the suc- 

 culent species when inspissated forming the gum Eu- 

 phorbium of commerce. They are chiefly found in 

 Europe and Africa. Those of the latter continent, veg- 

 etating in arid sandy grounds and deserts, have, like 

 the Cactuses of America, growing in like situations, 

 succulent, columnar stems, mostly destitute of leaves, 

 but often armed with clustered and scattered spines. 

 The general composition of their flowers and generic 

 character is as follows — They present a ventricose, or 

 cup-shaped involucrum, resembling a calyx, of which 

 the alternate segments are petaloid. The sterile flow- 

 ers, 12 or more, are generally simple ; each of them 

 consisting of a mere anther with its filament, articulat- 

 ed to a pedicel (and proving themselves, however sim- 

 ple, still to be so many distinct flowers by coming to 

 maturity at several successive periods). The calyx 

 and corolla is very rarely present. The fertile flower 

 is solitary, central, and stipitate (or pedicellate), with- 

 out either calyx or corolla. The styles are 3, each 



