OPHRYDE^SERAPIADIN^— ORCHIS 177 



unlike any other orchid (except 0. purpurea, which has equally dark-coloured buds). 

 The rounded top of the spike forms an admirable landing-stage for the fly, wliich 

 is many times bigger than the individual flower, and the nearly white flowers when 

 open show the visitor clearly where to begin work. One would never have suspected 

 that a plant with such tiny flowers would be visited by a fly as large as a bluebottle. 

 The change of colour of the sepals from dark almost blackish red-purple to nearly 

 white is most striking, the line of demarcation clearly indicating the most advan- 

 tageous flowers for the insect to visit. I afterwards saw a similar fly come once or 

 twice to the flowers but failed to catch it. 



5. Orchis morio L. 

 PI. 39. Green-veined Orchid 



Tubers globose or ovoid; roots few, short. Stem (10-50 cm.) erect, round, more or 

 less hollow, angled and tinged with violet above, with 2-3 whitish membranous 

 sheaths at base. Leaves lanceolate to oblong-lanceolate, acute or obtuse, keeled, 

 unspotted, broad-sheathed at base, green or bluish green, the lower spreading or 

 recurved, the upper 2-3 erect, rather broader, loosely clasping the stem, the upper- 

 most bract-like, membranous, acute, often purplish; nerves 1-2 on each side of mid- 

 rib with fainter nerves between and numerous cross-veins. Spike short, few-flowered 

 (6-12), lax. Flowers rather large, very faintly scented, red-purple, blue-purple, lilac 

 or pale mauve, rarely pink, still more rarely white, the sepals with conspicuous green 

 veins, the middle of the lip paler and spotted. Bracts lanceolate, acute or rather 

 obtuse, membranous, glossy, more or less tinged with purple, the lower 3-5 -nerved, 

 the upper shorter, i -nerved, all sheathing the ovary, which they equal, slightly exceed, 

 or sometimes fall short of. Ovary sessile, rather long, curved and twisted at the 

 summit, often purplish; ripe capsule long, triangular, with salient ridges. Sepals 

 forming a short almost globular helmet, ovate-oblong, concave, keeled, rounded at 

 the tip, with 3-7 conspicuous green or bronze-purple nerves, the upper sepal narrower, 

 oblong, 3-5 -nerved. Petals paler, shorter and narrower, linear-oblong, rounded and 

 concave at the tip, 1-3 -nerved, forming an interior hood beneath the helmet. Lip 

 transversely oblong, broader than long, side-lobes broadly rounded out and folded 

 back, mid-lobe short, broad, truncate, sometimes notched, usually shorter than but 

 sometimes equalling or slightly exceeding the side-lobes, edges toothed or slightly 

 crenate, the surface densely covered with very short minute papilla. Spur cylindrical, 

 rather long but shorter than the ovary, thick, horizontal or slightly curved upwards, 

 flattened, club-shaped, truncate and often notched at the tip, densely covered inside 



GBO 23 



