56 NATIVE BRITISH ORCHIDACEyE 



thorougUy stable species. The only variations known are such as generally occur in 

 all plants through the influence of unusually favourable, or unfavourable, circum- 

 stances, such as vigour of growth, height of stem, size of leaves, and number and 

 size of flowers. In shady places it is often tall — I found one specimen in damp open 

 woods above Sallanches, Haute Savoie, 68 cm. high, with a spike i8 cm. long with 

 1 5 flowers. A few white-flowered specimens have been found abroad. 



Habitat. "In England steep slopes in beech- woods on oolite or pea-grit at about 

 500-600 ft. elevation. The proportion of flowering plants is very small — in one year 

 only two out of 30. It disappears when the beeches are felled" (Wilfred Mathieson). 



Distribution. Apparently now only found in Gloucestershire; formerly found 

 on the Quantock Hills, Somerset (1836), and on Hampton Common. Europe from 

 Scandinavia southwards to Spain, Italy, etc., Caucasus, Asia Minor, Persia. 



Cephalanthera rubra Richard, Mem. Mas. Paris, iv, 60 (1818). Serapias 

 HelleborineS. L., i>.^/. ed. i, p. 949 (i753)- S. longifolia Hudson (1762) 

 in part. S. rubra L., Sjst. Nat. ed. 12, 11, 594 (1767)- Epipactis purpurea 

 Crantz (1769). E. rubra All. (1785), Wettstein (1889). 



Fertilisation. C. rubra, like C. ensijoUa, is entirely dependent on insects for 

 fertilisation — unvisited flowers set no seed-capsules — and the method of pollination 

 is the same in both. I inserted a dead bee, Osmia ledana $, into a flower of C. rubra, 

 withdrawing it so that it brushed lightly against the stigma and the face of the anther. 

 Both pollinia were removed with ease (/.L.i'. xlv, 513 (March, 1922)). I watched 

 C rubra in woods where it was frequent, and several times exposed cut flowers in 

 various likely places, but always without success. On June nth, 1922, near Challes- 

 les-Eaux, Savoie, while my wife was carrying several spikes in her hand, on passing 

 the place where we had previously gathered them, a red humble-bee came and visited 

 tliree flowers, but having no net, we could not catch it. Six days later, on a very 

 wet morning, a similar bee came to C. rubra in a mixed bunch of flowers on my 

 window-siU. I had no net, but he was so engrossed in the third flower I saw him 

 visit, that I caught him in a glass-lidded pill-box. He was identified by Monsieur L. 

 Berland of the Paris Museum as Bombus agrorum F. 



Colonel Evans, F.L.S., at Annegy, Haute Savoie, took the following bees visiting 

 C. rubra in June, 1950: Heriades nigricornis Nyl. (taken by Mrs Evans), bearing 

 pollinia; Heriades campanularun? Kirby. This small bee was very persistent in its visits, 

 and was taken in three distinct localities. Several were caught bearing remains of 

 pollinia on the thorax. It is the most frequent visitor of all. Emera longicornis per- 

 sistently flew round and round the flowers, but was too timid to visit them. Heriades 

 rapunculi L. and Osmia carulescens $ were also taken on the flowers bearing pollinia 

 at Annegy by Colonel Evans. 



