136 INTERESTING PLANTS OF ALPINE PASTURES 



rather small for examination, and we may therefore 

 postpone a description of them until we come to 

 discuss the similar structure of the Lesser Butterfly 

 Orchid. We may merely note that in the Black 

 Nigritella a very short spur is found. 



THE LESSER BUTTERFLY ORCHID. 



The Lesser Butterfly Orchid (Habenaria bifolia, 

 R Br.), sometimes called Platanthera Mfolia, Kich. 

 (Plate XXXI., Fig. 2), is easily recognised by the two 

 very large and broad leaves, and by the white flowers 

 with long spurs, twice the length of the ovary. The 

 general habit is otherwise not dissimilar to Nigritella, 

 except that the leaves, other than the two broad ones 

 arising from the base, are very few and reduced to 

 scales, and the spike is cylindrical in form and much 

 less dense. 



In shape the flowers are supposed to possess some 

 resemblance to a butterfly, just as other Orchid flowers 

 are likened to bees, spiders, and flies. Curiously 

 enough, the Lesser Butterfly Orchid is visited by 

 some nocturnal insects, and especially by Hawk- 

 moths (Sphinx). The clove-like scent of the flowers 

 is strongest towards evening, and attracts night-flying 

 insects. Only those with a sufficiently long and 

 slender tongue or proboscis can reach the honey 

 stored in the long spur. 



Let us now examine one of the flowers to see 

 how they are specialised for their insect visitors. The 

 floral envelope in the Orchids is not differentiated into 



