122 OUR NATIVE ORCHIDS 



swamp to his study table or moved himself and his micro- 

 scope to their neighbourhood. 



That the flowers are perfectly adapted to their insect 

 visitors is evident from the fact that as soon as a flower 

 withers on the stalk its ripened ovary begins to swell into an 

 ovoid, almost round, beakless capsule. 



KEY TO THE SPECIES OF ACHROANTHES 



Leaf sheathing the base of the stem, 



flowers whitish. I. White Adder' s-mouth. 



Leaf clasping the stem near the mid- 

 dle, flowers greenish. 2. Green Adder' s-mouth. 



I. WHITE ADDER's-MOUTH 



Achroanthes monophylla (L.) Greene. (Plate XLVIL, Fig. i.) 



Our two species of Adder's-mouth bear scientific names, 

 having exactly the same meaning. Monophylla is the 

 Greek version, and Uniflora the Latin, for "one leaf." 

 Therefore, no distinction is carried either in the specific 

 name, which is meant to be descriptive, or in the leaf itself, 

 except that in the White Adder' s-mouth species the leaf 

 clasps the stem near the root, and in the Green Adder's- 

 mouth it stands jauntily off at an oblique angle, almost 

 half way up the stalk. The White Adder's-mouth is a 

 very tiny plant, often not more than four inches high, never 

 more than six. The leaf is oval, and from one to two inches 

 long. The raceme, which may be from one to three inches in 

 length, is not a half-inch thick. This indicates how minute 

 must be the flowers that stand erect on either side, on tiny 



