138 NATIVE BRITISH ORCHIDACE^ 



with a long whitish staminode at base; upper part (anther) an upright green membrane 

 (connective) curved forwards Ulce a horseshoe (in section), convex (not grooved) 

 behind, ending on each side in a white anther-cell. Cells erect, paraUel, ± 2 mm. 

 long, close together, partly conceahng the stigma. Pollinia small (including caudicles, 

 2 mm. long)," twice as long as caudicles, cream-coloured, divided to base mto two 

 parallel leaves, in side-view pear-shaped, attached sideways to the small oval orange- 

 yellow viscid discs by one corner of the truncate foot of the caudicle, the other 

 corner projecting like a tiny spur. Stigma on lower front of column, not extending 

 below entrance of spur, magnet-shaped in horizontal section, with very thick edges. ^ 

 Habitat. Woods, heaths, hillsides, pastures and marshes, with a fondness for 

 damp places. Flowers late May to July. 



Distribution. Throughout Great Britain and Ireland, except perhaps in the extreme 

 north of Scotland. Europe from Scandinavia and Mid-Russia to the Mediterranean 

 and N. Africa; Siberia, Caucasus, Asia Minor, China. 



Platanthera bifolia Rchb. p., Fl. Germ. exc. p. 120 (1830). Orchis bifolia 



L. (p.p.) (1755). O. ALBA Lam. (1778). Habenaria bifolia R. Br. (1809). 



Lysias bifolia Salisb. (1812). 



Fertilisation. Darwin examined two moths, Agrotis segetum and Anaitis plagiata, 



one with three pollinia, the other with five, attached, not to the eye or the side of 



the face, as in P. chlorantha, but to the base of the proboscis. The distance between 



the viscid discs, which is only about a quarter of that in P. chlorantha, is thus nicely 



adjusted to coincide with the space between the points of attachment. To accomplish 



this, the anther appears to have been folded sideways, until in section it is like a 



magnet, or the letter U inverted. Darwin found that the viscid matter of the disc, 



after having been dried for several months, when moistened became as adhesive 



as ever.2 



Flatanthera bifolia x Orchis maculata (p. 217), vide Orchis maculata. 



PLATANTHERA BIFOLIA x CHLORANTHA 

 X P. hybrida Brug. 



A specimen found by me near Chambery, Savoie, June 8th, 1928, resembled P. chlo- 

 rantha in its habit, stout stem, broad spike, large flowers, broad bracts, and green- 

 edged stigma, and P. bifolia in its narrower sepals, column bent into a U, ridged at 

 the back, and parallel anther-cells only 2 mm. apart (in one or two flowers 3 mm.). 

 Roughly spealdng, it had the general appearance of P. chlorantha, intermediate flowers, 



■ A specimen without spurs (lusus ecalcaratd) was found near Exeter. B.B.C. p. 149 (1920)- 

 » 'Pert. Orch. ed. 2, p. 251. 



