Platanthera L. C. M. Richard

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 : 331

13. Platanthera L. C. M. Richard 1

Stock usually with tubers. Leaves few, usually only the lowest 1-3 well developed, the upper reduced to sheaths or with a small, bract-like lamina. Flowers white or green, in a usually fairly dense spike. Outer lateral perianth-segments patent, the inner lateral shorter, connivent with the outer median to form a galea. Labellum linear-oblong to rhombic-lanceolate, entire. Spur more or less cylindrical. Stigma single, flat; rostellum inconspicuous. Viscidia distinct; bursicles absent.

1 Spur 18-30 mm, longer than ovary 2 Anther-lobes parallel, almost contiguous; spur acute

1. bifolia 2 Anther-lobes convergent above, but widely separated below;

spur somewhat dilated at apex 2. chlorantha 1 Spur2-8 mm, shorter than ovary 3 Stem with 1 well-developed leaf; spike with 3-6 flowers

5. obtusata 3 Stemwithat least2 well-developedleaves; spikewith

numerous flowers 4 Lowest 2 leaves much larger than the others 3. micrantha

4 Lowest 2 leaves not contrasting markedly with the others,

the second and third from the base being usually the largest 4. hyperborea