8 OUR NATIVE ORCHIDS 



like opening on one side of the column. But his struggles 

 are not yet ended, for his egress is still slightly checked 

 by the narrow dimensions of the opening, and also by the 

 detention of the anther, which his thorax has now en- 

 countered. A strange etiquette this of the Cypripedium, 

 which speeds its parting guest with a sticky plaster smeared 

 all over its back." 



This genus is the easiest of our American orchids to 

 name. The pouch, or labellum, is the sign that they belong 

 to the genus Cypripedium, and their colour indicates the 

 species to which they belong. 



KEY TO THE SPECIES OF CYPRIPEDIUM 



Greenish, with purple streaks. i. Ram's-head Lady's-Slipper. 



Pink or rose purple. 2. Pink Lady's-Slipper. 



White. 3. Showy Lady's-Slipper. 



4. Small White Lady's-Slipper. 



Yellow. 5. Large Yellow Lady's-Slipper. 



6. Small Yellow Lady's-Slipper. 



I. r.\m's-head lady's-slipper 



Cypripedium arietinum, R. Br. (Plate III.) 



The rarest of our native Cypripedium is the tiny Ram's- 

 head, Cypripedium arietinum. Through the northern part 

 of New England, New York and Minnesota it grows shyly 

 in cold, damp woods or under pines and cedars, blooming 

 from May until August, according to locality. It is unable 

 to attract, by reason of its less conspicuous flower, any but 



