INTRODUCTION. 



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parts only, and those frequently not very obvious, have been termed artificial characters f 



disfnction. The memory, by these means, is relieved from a multiplicity of minute distin f ^ 



which would not be the case were all the parts of the plant included in the essential specificT' 



scription or character. 



Though most of the genera are considered as merely artificial, yet there are several whi h 

 have their nutntive matters of a description peculiar to themselves. Sir Humphry Davy ' f 

 us, that the nutritive matters from the difFer-ent species of fescue, in general, afford moreWtter 

 extractive matter than those from the different species of poa, and that the seed crop of the 

 Phleum pmtense afforded more sugar than any of the poa or fcstuca species ' 



M. St. Hilaire, in his Exposition of the Natural Families of Plants*, arranges o,asses ac 

 cordmg to the number of the styles, the stamina, and the number of florets contained in each 

 calyx. Accordingly lie divides grasses into ten sections. 



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Sect. I. Contains such grasses as have 2 styles, and 1, or 2 stamina. 



11. Grasses which have 2 styles, 3 stamina, and the calyx 1-flowered. 

 III. Grasses furnished with 2 styles, 3 stamina, calyx containing two flowers, one of 



IV. 



which consists of stamina only. 

 Grasses which have 2 styles, 3 stamina, calyx 2, or S-flowered, the fl 



rent sexes. 



owers of difFe- 



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V. Consists of grasses which have 2 styles, 3 stamina, calyx 1, or 2-flowered, all th 



flowers bisexual. 



e 



VL 

 VII. 



Grasses furnished with 2 styles, 3 stamina, calyx many-flowered, flowers glomerated 

 Grasses with 2 styles 3 stamina, calyx many-flowered, flowers in a spike, or situated 

 on the axds of the stalk,, terminating floret male, or barren. 

 VIII. Contains the grasses which have 2 styles, 3 stamina, and calyx many-flowered. ' 

 IX. Grasses with 2 styles, and 6, or more stamina. 

 X. Grasses which have their style unique, summit simple, and 3 stamina. 



^Z^:ti^ T- ""-'T^^^' ■- -"- -e obvious; yet, like all 



possess characters tt I 't 1 T^ '''' '"^'T' '' ''''' ''' ''''''' ''-'^ -'-' 

 fl f ^"^ *° "" P^^^« 1" ™ore than one section. For practical purnose^ 



* 



Exposition des Families Naturelles et rlp U r ■ .• -. r.^ - .. 



ureues, et de la Germination dcs Planter, par Jaume gt. Hilaire. Paris, 1805 



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