THE GLASSES DODECANDRIA AND ICOSANDRIA. 



161 



CLASS XI. DODECANDRIA. 



Hitherto the classes have succeeded each other by the addition of one stamen ; but 

 this addition is of two, there being no English plant with eleven stamens. The order 

 contains but five genera and eight species (each plant having twelve stamens), sub- 

 divided into five classes viz., Monogynia, Digynia, Trigynia, Tetragynia, and Dodeca- 

 gynia, (twelve pistils). The genus and species Sempervivum tectorum, wr House- 



. 330. 

 Dodecandria Tetragynia. 



Fig. 331. 

 Dodecandria Trigyma. 



Fig. 332. 

 Dodecandria Digynia. 



leek, is the best known, and belongs to the order Dodecagynia ; after which may be 

 placed the Agrimonia Eupatoria or Agrimony (Digynia), and then Reseda (Trigynia), 

 and Asarum and Lythrum (Monogynia). The Agrimonia is presumed to possess slight 



Fig. 333. Dodecandria Monogynia. 



Fig. 334. Dodecandria Polygynia. 



medicinal properties ; but the whole class is deficient, not only in number, but ia 

 beauty and utility. 



CLASS XII. ICOSANDKIA. 



This is a most interesting class of plants, second, if at all, only to Triandria ; and is 

 one of those which chances to be well comprised in the Linnsean system. It contains 

 twelve genera and sixty-seven species ; and, with the exception of the Pyrus Aucuparia, 

 or Mountain Ash, is either edible or harmless. It is dis- 

 tinguished less by the number than the position of the 

 stamens for there are an indefinite number of stamens 

 but they are attached to the calyx (Epigynous, Fig. 218 

 and so distinctive is that arrangement, that a member o 

 the class is instantly recognized. 



It is divided into three orders Monogynia, Pentagy- 

 nia, and Polygynia. Prunus, or the Cherry and Black- 

 thorn, is the only occupant of the first order ; whilst three 

 delicious plants Mespilus or Hawthorn and Modiar, 

 Fynis (Pear, Apple, and Crab), and Spiraea or Meadow-sweet have from two to nv 



VOL. II. '*? 



Fig. 335. An losandrous 

 flower. 



