174 PROCEEDINGS: BOSTON SOCIETY NATURAL HISTORY. 



Manual. In such cases the name used in the Manual follows in 

 parentheses. For the convenience of those who use Britton and 

 Brown's Illustrated Flora, the name used in the second (1913) edition 

 of that work is also given in parentheses wherever it differs (except 

 in spelling) from that used in this list. If the generic name used by 

 Britton and Brown differs from that here used but the specific names 

 are the same (except for changes of gender), the generic name only is 

 given. The Illustrated Flora, as is well known, does not recognize 

 geographical varieties to the extent of naming them. It will be impos- 

 sible therefore, for those who use the Illustrated Flora to discriminate 

 between the species and the many varieties (over two hundred) recog- 

 nized in this list. 



A great number of our native plants are not sufficiently known by 

 the people to have received a genuine popular name. Only striking 

 plants, like the Cat-tail, Sweet Flag, and Butterfly-weed, have names 

 that are actually current. Others belong to a group which is recog- 

 nized, like Cotton Grass, but species within the group are not dis- 

 tinguished. Many vernacular names are given in the botanies, that 

 are never used by the people, such as Dock-leaved Persicaria {Poly- 

 gonum lapathifolium). In the following list all names known to be in 

 current use are given, and others have been copied from the Manual. 



The habitats given are those observed in the County. 



The use of the expressions valley and plateau demands a word of 

 explanation. The term valley is used to designate the trough formed 

 by the Hoosic and Housatonic Rivers and their main tributaries. It 

 contains the principal limestone and moraine deposits, and its slopes 

 include wooded hillsides with well-drained leaf mould. The term 

 plateau is used to designate the broad upland bounding the valley on 

 the east. It is characterized by an absence of limestone and by cool 

 rocky woods, ill-drained hillsides and moist fields {vid. Introduction, 

 p. 182). 



For convenience, the term Greylock is used to include the whole 

 mountain-mass that culminates in Mt. Greylock of the topographic 

 sheet, and The Dome for the mountain-mass that culminates in Mt, 

 Everett of the topographic sheets. 



To indicate the comparative frequency of the plants listed the fol- 

 lowing terms have been used, namely, "common," "frequent," "occa- 

 sional," and "rare." These terms must be interpreted in connection 



