O. muscifera: tuberous; slender; flowers few, small; sepals greenish; lip oblong, considerably lengthened beyond the sepals, purplish-brown, with pale blue or white central marks, convex, with the lateral lobes turned down, and the central one deeply notched. - Fly Orchis. - Chalky pastures. Fl. May, June.
O. aranifera: tuberous; flowers few, distant; sepals greenish; lip scarcely longer than the sepals, broad, convex, hairy, dull brown, inscribed with pale-yellowish markings in the centre, the edges obscurely lobed and scarcely turned under. - Spider Orchis. - Chalky pastures. Fl. April.
Var. fucifera: lip usually undivided, obovate, longer than the sepals. - Chalky pastures.