NEOTTIEjE— LISTER A 99 



Habitat. Woods and shady places, hedge-banks, moist pastures. Frequent and 

 locally abundant. Flowers June to July. 



Distribution. Throughout Great Britain and Ireland to Orkney and Shetland. 

 Europe from Scandinavia to Spain, Italy, Corsica, the Balkans, Mid- and S. Russia, 

 the Urals, Caucasus, Siberia. 



LisTERA ovATA R. Br. in Ait. HorL Kew. v, 201 (1813). Ophrys ovata L., 

 Sp. pi. ed. I, p. 946 (1753). Epipactis ovata Crantz (1769). Helleborine 

 ovata Schmidt (1794). Neottia latifolia Rich. (1818). 



Fertilisation. One might easily jump to the conclusion that the green incon- 

 spicuous flowers of L. ovata were self-fertilised, but this is far from being the case. 

 Although apparently uninteresting, they are provided with a wonderful mechanism 

 for attaching the polUnia to insects, somewhat suggestive of a contact mine which 

 explodes when touched. Down the centre of the lip above the fork there is a gHstening 

 streak of free nectar which is so attractive to small bees and flies that the flowers are 

 visited over and over again. I have even seen hive-bees going to them. Darwin 

 saw a Hamiteks and a Cryptus crawl into the flowers, and suddenly retreat with a 

 pair of bright yellow pollinia adhering to their foreheads.' The rostellum consists 

 of a tongue-like membrane growing from the upper edge of the stigma, at iirst 

 directed obHquely upwards, its point near the tip of the anther. Its upper surface 

 is concave, and the anther, just above it, opens in bud, and deposits the two pollinia 

 upon it, where they lie free, their thin ends near its tip. The tips of the anther, the 

 rostellum, and the pollinia are nearly touching. The rostellum is internally divided into 

 a series of cells which contain very adhesive matter, and have the power of violently 

 expelling it. The rostellum is sensitive, and if touched ever so lightly beneath, a kind 

 of explosion occurs. A drop of very adhesive fluid is instantly expelled from each 

 of the two little hollows near the tip, at once coalescing to form a bigger drop wliich 

 catches the two ends of the pollinia and fastens them to the touching object. The 

 fluid is at first somewhat milky, but in less than a second a film forms over it, and 

 in two or three seconds it sets hard in a soUd mass. The rostellum is so exquisitely 

 sensitive beneath that a touch from the thinnest human hair is enough to cause the 

 explosion, and so accurate is the adjustment that the tips of the pollinia are always 

 caught and attached to the touching object. Never once did Darwin find this fail. 

 Moreover, so rapidly is this done that it is difficult to touch the rostellum with a 

 needle, however quickly, without removing the pollinia. ^ 



The arrangements for leading the unsuspecting insect into this trap are as ingenious 

 as the trap itself. The insect crawls up the lip, following the trail of honey tdl it 

 reaches the angle where the lip bends, almost at right angles, towards its base. There 



I Darwin, Vert. Orch. ed. 2, p. 122. » Uid. p. 118. 



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