INTRODUCTION. II 



and 15th, and in the White Mountains, two weeks later still; 

 that is, in low or moderately elevated land. Between Portland, 

 Maine, and Moosehead Lake, there is thought to be a differ- 

 ence of at least two weeks in plants that bloom in spring ; 

 " this difference lessening as the hot weather comes on." The 

 amateur collector will find that it makes a good deal of differ- 

 ence in point of time, whether his search is made on the north 

 or south side of an elevation ; whether in shaded or open 

 ground ; and, moreover, will often discover that the county 

 map on which he has relied is of little use in locating 

 " stations," for he can never be sure that the plants he has seen 

 in one swamp will occur in a corresponding swamp in the 

 next township ; and, indeed, it is highly probable that 

 species abundant on one side of a mountain range will en- 

 tirely disappear when he reaches the other side. In the case 

 of Eastern Massachusetts, to give a clearer illustration, cer- 

 tain Orchids grow within thirty miles of Boston, but one's 

 success in getting them depends chiefly on whether he meas- 

 ures the thirty miles north or south of the city. The subtle 

 influences of soil and climate sometimes contradict one's 

 learned conjectures very unpleasantly. 



I am indebted to Professor Gray for permission to make 

 liberal extracts from his Manual, to Rev. Henry P. Nichols 

 of New Haven, Conn., Dr. N. L. Britton of Columbia Col- 

 lege, and especially to my friends Henry H. Donaldson and 

 Frederick H. Horsford, to whom this work is informally dedi- 

 cated. 



ORCHIS FAMILY IN NEW ENGLAND. 



(Synopsis from, and mainly as arranged in Gray's Manual.) 



I. Anther only one. (The 2 cells should not be mistaken 

 for anthers !) 



Tribe I. OPHRYDEvE. Anther (of 2 separate cells) borne 



