Listera R. Br.

Tutin, T. G., Heywood, V. H., Burges, N. A., Moore, D. M., Valentine, D. H., Walters, S. M. & Webb, D. A., 1980, Flora Europaea. Volume 5. Alismataceae to Orchidaceae (Monocotyledones), Cambridge: Cambridge University Press : 329

7. Listera R. Br. 1

Plants with short rhizome and slender roots. Leaves usually 2, subopposite, sessile, borne just below middle of stem. Inflorescence a rather lax, spike-like raceme. Perianth-segments subequal, patent or somewhat convergent. Labellum 2-3 times as long as other segments, deeply 2-fid distally, rarely with 2 small basal lobes, secreting nectar in central furrow; spur absent. Column short, erect. Rostellum wide, flat. Viscidia absent; bursicles absent.

Leaves 5-20 cm; raceme 7-25 cm, many-flowered 1. ovata Leaves 1-2-5 cm; raceme 1-5-6 cm, 4- to 12-flowered 2. cordata