330 DIDYNAMIA. 



the calyx, four, except in Phryrna, which has a 

 solitary seed. Corolla monopetalous and irregular, 

 a little inflated at the base, and holding honey, 

 without any particular nectary. Stamens in two 

 pairs, incurved, with the style between them, so that 

 the impregnation rarely fails. The plants of this 

 order are mostly aromatic, and none, I believe, 

 poisonous. The calyx is either in five nearly equal 

 segments, or two-lipped. Most of the genera afford 

 excellent essential characters, taken frequently from 

 the corolla, or from some other part. Thus, 



Per ilia has two styles, of which it is an unique 

 example in this class. 



Mentha a corolla whose segments are nearly 

 equal, and spreading stamens. Engl.Bot. t. 446 8. 



Lavandula the Lavender, and Jestringia> Tracts 

 on Natural History, Q77,t.3, have a corolla resu- 

 pinata, reversed, or laid on its back. 



Teucrium a deeply divided upper lip, allowing 

 the stamens and style to project between its lobes. 

 Engl. Bot. t. 680. 



Ajuga scarcely any upper lip at all, t. 77 and 489. 



Lamium has the mouth toothed on each side, 

 t. 768. 



Prunella, t. 961, has forked filaments ; Cleonia 

 four stigmas ; Prasium a pulpy coat to its seeds. 

 These instances will suffice as clear examples of 

 natural genera, distinguished by an essential tech- 

 nical character, in a most natural order. 



