Cypripedium calceolus, L., 1753, 1753

D. M. Moore (ed.), 1980, CCIII Orchidaceae, Flora Europaea, Vol 5: Alismataceae to Orchidaceae, Camebridge: Cambridge University Press, pp. 325-350 : 326

1. C. calceolus L.,

Sp. PI. 951 (1753).

Rhizome long. Stem 15-50 cm, glandular-pubescent, with brown basal sheaths. Leaves 3-4, (7—)10—17 x 3*5—7(—10) cm, elliptical to ovate- oblong, acute to acuminate, sparsely pubescent. Flowers 1 (—3), subtended by a large leaf-like bract. Perianth-segments 6-9 cm, reddish-brown, rarely yellow-green (f. viridiflorum Blytt); outer median 3-5-5 cm, ovate- to elliptic-lanceolate, the lateral forming a slightly narrower, downward-pointing bifid segment; inner 4-6 cm, asymmetrical, linear-lanceolate, acuminate. Labellum c. 3 cm, shorter than other perianth-segments, obovoid, rounded at apex, pale yellow, with reddish spots inside. 2n = 20.

Woods and meadows; calcicole.

N., C., E. & S. E. Europe, westwards to Norway and the S. W. Alps; isolated stations in N. England and the E. Pyrenees. Much rarer than formerly over much of its range. Au Br Bu Cz Da Fe Ga Ge Gr He Hs Hu It Ju No Po Rra Rs (N, B, C, W, K, E) Su.