THE ESSENTIAL ORGANS STAMENS. 



125 



(fig. 236), when there are four long stamens and two short ones, 

 characteristic of the Cruciferae. When the stamens are of unequal 

 length in the same flower, or in diiferent flowers of the same 

 species (e. g. Primrose), the condition is called dimorphic, and has 

 reference to the mode of fertilization to be hereafter mentioned. 



The term included is employed to denote that the stamens do 

 not reach beyond the corolla ; exserted, that they are protruded 

 from it ; while declinate means that the exserted stamens are all 

 curved over to one side. 



Cohesion, etc. The stamens are subject to apparent confluence 

 or cohesion, like the other organs. If the filaments are only 



Fig. 234. 



Fig. 235. 



Fig. 236. 



Fig. 234. Corolla of Glechoma, laid open to show the didynamous stamens. 

 Fig. 235. Corolla of Digitalis, laid open to show the didynamous stamens. 



Df the "" 



Fig. 236. Tetradynamous stamen 

 lopes being removed. 



' the Wallflower surrounding the pistil, the floral enve- 



partially separated so that they form a tube surrounding the 



Fig. 238. 



Fig. 237. ^ Fig. 240. 



Fig. 239. 



Fig. 237. Monadelphous stamens of Malva. 



Fig. 238. Diadelphous stamens of Leguminosse. 



Fig. 239. Ground-plan of a Papilionaceous flower with diadelphous stamens 9 + 1 (the 



little circles round the solitary carpel). 

 Fig. 240. Triadelphous or polyadelphous stamens of Hypericum ceffyptiaeum. 



