209 



THE GENUS EPIPACTIS IN BRITAIN. 



Br T. Stephenson, D.J)., and T. A. Stephenson, M.Sc. 



(Plate 555.) 



We have made the critical species of the genera Orchis and JEpi- 

 27actis our study for several 3"ears, and had prepared a paper on the 

 subject with numerous illustrations, which we find would be too 

 costly to produce as a whole ; but we hope to print two of the plates 

 and the more important part of the text in a series of short con- 

 tributions to this Journal. The Plate accompanying the present note 

 will illustrate some of our points with reference to Ejnpacfis, the 

 next communication will deal similarl}^ with Orchis. We are publish- 

 ing the Plates first, with a summary of our ideas corresponding to 

 each, so that reference can be made to the figures in later papers 

 amplifying the text of the summaries. 



Our present concern is with Epipactis. We have had unusually 

 good opportunities of observing numerous specimens of the commonest 

 forms, and also, to a lesser extent, the rare ones. The main part of 

 our material for the JE. lafifoUa group is from Aberystwyth, but we 

 have obtained living specimens from various distant localities for 

 confirmation. We would add a warning that nothing can he done 

 with the genus Epipactis from pressed plants, and but little with 

 Orchis — fresh material is essential. By wa}^ of compensation, it is 

 ver}^ easy to preserve the flowers in spirit — the colour, of course, is lost, 

 but the form is perfectly retained and without shrinkage. 



Our conclusion is quite definitely that the genus Epipaciis is 

 represented in Britain by five good species only : — E. palusiris 

 Crantz, E. atropurpurea Baf., E. viridijiora lichb., E. purpurata 

 Sm., E. latifolia AUm. 



E. pahistris is so distinct that it requires no comment, E. cdro- 

 purpurea ( = E. ovalis Bab., = -£J. ruhiginosa Crantz, — i\ atroruheiis 

 Sell.) is, in our experience (we have seen forms from Great Orme, 

 Ireland, and Grassington), quite easily recognised and not to be con- 

 fused with E. latifolia at all. Its small flowers with a broad epichile, 

 which has usually 3 very rugged elevations, often confluent, its rough 

 ovary, and its small neat leaves, the bottom one usually purple 

 beneath, are points which distinguish it from E. latifolia, apart frqm 

 its typically small size and often rich dull purple flowers. Even if 

 the flowers are green, however, other points distinguish it. 



E. purpurata ( = E. violacea Bor,, = jE'. sessili^ora Peterm.) is 

 equally distinct. Whether or not the stems grow in tufts, the leaves 

 are generally much smaller and more delicate in texture than in 

 E. latifolia, and are tinted with a fine violet which turns their green 

 to grey, except in an odd plant here and there Avhich has green but 

 delicate leaves. The bracts may be very long and narrow. The 

 flower seems to have a constant colour-scheme — the ovar^^ dark green 

 or purple-tinged, the petals pale whitish green, the sepals more 

 definitely green, especially outside, the lip whitish green with usually 

 pale lilac elevations on the epichile. The lip usually has a more or 



JOUENAL OF BOTANT. — VoL. 5S. [SePTE^IEEB, 1920.] R 



