Spiranthes L. C. M. Richard, 1818

D. M. Moore (ed.), 1980, CCIII Orchidaceae, Flora Europaea, Vol 5: Alismataceae to Orchidaceae, Camebridge: Cambridge University Press, pp. 325-350 : 330

8. Spiranthes L. C. M. Richard 1

Roots fleshy, more or less tuberous. Spike-axis twisted, so that flowers are arranged in one or more spiral rows. Perianth- segments subequal, free or variously connate or connivent. Flowers fragrant, geniculate or arcuate, the ovary suberect, the perianth and column horizontal. Labellum about equalling the other perianth-segments, oblong, entire. Spur absent. Rostellum deeply 2-fid, with narrow, acute lobes, between which lies the single visicidium; bursicles absent. Anther largely hidden behind rostellum.

.1 Leaves ovate-elliptical, patent, in a basal rosette; cauline leaves reduced to scales 1. spiralis

1 Leaves linear-lanceolate to narrowly oblong, ± erect, some of them cauline

2 Flowers in one spiral row; bracts 6-7 mm; leaves obtuse 2. aestivalis

2 Flowers in 3 spiral rows; bracts 10-17 mm; leaves acute 3. romanzoffiana