HOODED LADIES-TRESSES 



Ibidium strictum (Rydberg) House 



Hooded ladies-tresses is later in blooming than most of our native 

 orchids, and often delays flowering until the end of summer. It grows 

 in moist or swampy places, in low meadows or near the borders of 

 streams. It is a very sweet-scented plant and is often abundant where 

 congenial soil and moisture conditions exist. Cross-pollination of the 

 flowers is insured by their intricate structure, and bees carry the pol- 

 len from one flower to another. Darwin's interesting observations on 

 this process have been recorded in great detail, and he and Asa Gray 

 had an extensive correspondence upon the subject. 



The plant has a wide range, extending in one form or another from 

 Pennsylvania to Newfoundland, New Mexico, California, and Alaska. 

 Perhaps more than one species is included in this citation of range, 

 as those from the east and from the west look rather dissimilar. 



The flowers sketched were obtained in the Siffleur River Valley, 

 fifty miles by trail north of Lake Louise, Alberta, at an altitude of 

 4,5 00 feet. 



PLATE 356 



