EXPLANATION OF PLATES. 149 



PLATE 15. CONTINUED. 



12. Icosandria, 20 or more stamens inserted into 



the calyx ; Pear, Pyrus communis. 



tn this specimen the five stamens opposite the segments of the 

 calyx are shorter than the rest. 



B. 



13. Polyandria, stamens more than 20, inserted 



into the receptacle ; Celandine, Chelidonium 

 majus. 



14. Didyriamia, stamens 2 long and 2 short ; 



Selfheal, Prunella Pennsylvania. 



a. The flower. 



b. The stamens and pistils shown separate and magni- 



fied. 



In tlje genus Prunella the filaments are forked, and the anther 

 borne on one point of the fork, as seen in the figure. 



15. Tetradynamia, stamens 4 long and 2 short ; 



White Mustard, Sinapis alba. 



a. The flower of the natural size. 



b. The stamens and pistil magnified. 



c. Glandular nectaries at the base of the stamens. 



d. One of the petals. 



16. Monadelphia, stamens united by their fila- 



ments into one tuhe ; Mallow, Makca. 



a. The flower. 



b. The stamens and pistil separated from the other 



parts of the flower. 



c. The tube of the united filaments. 



d. The anthers. 



e. The styles passing through the tube and appearing 



at top like a pencil. 



An example also of the order Polyandria, having many stamens. 

 IS* 



