512 THE AKTIFICIAL SYSTE5I OF LlNNuEUS. 



989. The classes and orders Liniifeus founded entirely upon the 

 number, situation, and connection of the stamens and pistils ; the 

 office and importance of which he had just set in a clear light. 



990. The classes, twenty-four in number, were founded upon 

 modifications of the stamens, and have names of Greek derivation 

 expressive of their character. The first eleven comprise all jjlants 

 with perfect flowers, and with a definite number of equal and un- 

 connected stamens. They are distinguished by the absolute number 

 of these organs, and are designated by names compounded of Greek 

 numerals and the Avord andria (from avr]p), which is used meta- 

 phorically for stamen, as follows : — 



Class 1. MoNAKDKiA includes all such plants Avith one stamen to 

 the flower ; as in Hippuris. 



2. DiANDRiA, those with two stamens, as in the Lilac. 



3. Triandria, with three stamens, as in the Valerian, «fec. 



4. Tetrandria, with four stamens, as in the Scabious. 



5. Pentandria, with five stamens, the most frequent case. 



6. Hexandria, with six stamens, as in the Lily Family, &c. 



7. Heptandria, with seven stamens, as in Horsechestnut. 



8. Octandria, with eight stamens, as in Evening Primrose, «Ssc. 



9. Enneandria, with nine stamens, as in the Rhubarb. 



10. Decandria, with ten stamens, as in Ehododendron. 



11. DoDEC ANDRIA, with twclvc stamens, as in Asarum and 



the Mignonette ; extended also to include those with 

 from thirteen to nineteen stamens. 



991. The two succeeding classes include plants with perfect flow- 

 ers, having twenty or more unconnected stamens, which, in 



12. IcosANDRiA, are inserted on the calyx (perigynous, 467), 



as in the Rose Family ; and in 



13. PoLYANDRiA, ou the receptacle (hypogynous, 466), as in 



the Buttercup, Anemone, &c. 



992. Their essential characters are not indicated by their names; 

 the former merely denoting that the stamens are twenty in number ; 

 the latter, that they are numerous. — The two following depend upon 

 the relative length of the stamens, namely, 



14. Did YN AMI A, including those with two long and two short 



stamens (Fig. 407) ; and 



15. Tetradynamia, those with four long and two short sta- 



mens, as in Cruciferous flowers (Fig. 406). 



