I40 NATIVE BRITISH ORCHIDACE^ 



being less spreading than in Gymnadenia, which, although it alters the appearance 

 of the flower, is hardly a ground for generic diiferentiation. 



Sclilechter^ adopts Meyer's genus, which he endeavours to support by two new 

 characters: (i) Viscid glands sub-orbicular instead of linear or oblong as in Gymna- 

 denia. (2) Rostellum erect, forked, with an ear on each side at the base surrounding 

 a naked round viscid gland. In Gymnadenia he gives "rostellum at base with two 

 upright or slightly diverging little plates with the two naked oblong or linear viscid 

 glands resting on the lightly forked outer edge". 



As to (i), in all the living specimens of G. alhida I have seen in France, Switzerland 

 and Britain the pollinia were inserted at the forward end of a linear gland, as m 

 Gymnadenia, and Darwin records the same of British specimens. ^ It therefore appears 

 to be a true Gymnadenia in this respect. The second character needs a dissecting 

 microscope to detect, and appears to be too unimportant to justify the creation of 

 a new genus, being merely a slight difference in the method of support of the viscidium. 

 Fertilisation. Gymnadenia is organised for visitation by Lepidoptera, as shown: 

 (i) by the viscid glands to wliich the pollinia are attached being long and narrow 

 so as to adhere longitudinally to the proboscis, and thus secure a firmer hold; (2) m 

 the case of G. conopsea, by the length of the spur, containing nectar only at the apical 

 part, which prevents all insects except those with a long proboscis from reaching it. 

 There are no guiding plates on the lip as in Anacamptis (which is also specially 

 adapted for Lepidoptera), so that there is notliing to compel the insect to stand on 

 the exact centre of the lip. This is not necessary, as it is an advantage rather than 

 otherwise for the viscid gland to be affixed to the side of the proboscis, as the pollinia 

 are then in better position to come in contact with the lateral stigmas. The poUima 

 when withdrawn are erect, i.e. at right angles with the narrow viscidium. After 

 the downward movement, they become parallel with the viscidium and therefore also 

 with the straightened proboscis to which it is affixed. If the pollinia are withdrawn 

 on a bristle, and if this be inserted, after the movement of depression, into the spur 

 of a flower, the two ends of the pollen-masses will accurately strike the two very 

 adhesive stitrmatic surfaces, situated on each side of the mouth of the spur.3 



I. Gymnadenia conopsea R. Br. 



Pis. 26 B, 27 and 29 A; PL F, fig. 2 (p. 123). Fragrant Orchid 



Tubers two, palmate, with 3-6 rather tliick tapering obtuse segments; roots few, 

 short, rather thick. Stem erect, 15-40 cm. (up to 60 cm. abroad), round, green, 

 leafy, angled or smooth, sometimes tinged with violet and slightly hollow above, 



' Fedde, Kepert. xvi, 266, 269 (191 9). 



^ Fert. Orch. ed. 2, p. 68. 3 Ibid. p. 67. 



