O R C H I D A C E A E, Juss.

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

C C I I I. O R C H I D A C E A E 1

Perennial herbs with rhizomes, vertical stock or tuberous roots, terrestrial, sometimes saprophytic, usually with mycorrhiza. Stems sometimes swollen at base to form pseudobulbs. Leaves entire, spirally arranged or distichous, rarely subopposite, reduced to scales or sheaths in saprophytes. Inflorescence a spike or raceme. Flowers zygomorphic, epigynous, usually hermaphrodite. Perianth-segments 6, in 2 whorls; median inner segment (labellum) usually larger and of different shape from the others, usually directed downwards owing to the ovary or the pedicel twisting through 180°, often with basal spur. Anthers and stigma borne on a column formed from fused filaments and style; stamens 1, rarely 2, with sessile or subsessile, 2-locular anthers behind or at the summit of the column; pollen-grains single or in tetrads, bound by elastic threads in packets (pollinia) which may be narrowed into a sterile, stalk-iike caudicle. Ovary inferior, 1 -locular, with parietal placentation, rarely 3-locular; stigmas 3, all fertile, or with the median sterile and often consisting of a beak-like process (rostellum) between the anthers and fertile stigmas; rostellum often forming 1 or 2 viscid bodies (viscidia) to which the pollinia are attached; viscidia sometimes enclosed in 1 (2), simple or 2-lobed, membranous, pocket-like outgrowths (bursicles) of the rostellum. Fruit a capsule, dehiscing by 3 or 6 longitudinal slits; seeds numerous, minute, with undifferentiated embryo and no endosperm.

Literature: E. G. Camus, Iconographie des Orchidées d'Europe et du Bassin méditerranéen. Paris. 1921; Texte. Paris. 1929. G. Keller, R. Schlechter & R. von Soô, Monographie und Iconographie der Orchideen Europas und des Mittelmeergebietes 1 -5. Berlin. 1925-1944. H. Sundermann, Europäische und mediterrane Orchideen. Hildesheim. 1975.

1 Plant without green leaves

2 Spur long, slender

3 Labellum entire, directed downwards 4. Limodorum

3 Labellum 3-lobed, directed upwards 5. Epipogium 2 Spur very short or absent

4 Stem with numerous scales; labellum c. twice as long as other

perianth-segments 6. Neottia

4 Stem with 2-4 scales; labellum about as long as other

perianth-segments 31. Corallorhiza

1 Plant with green leaves or green, bract-like scales on a green

stem

5 Flowers without a spur

6 Labellum large, inflated, slipper-shaped

7 Plant with solitary pseudobulb and one foliage-leaf;

anther 1 32. Calypso

7 Plant with creeping rhizomes and 2-4 foliage-leaves;

anthers 2 1. Cypripedium

6 Labellum neither inflated nor slipper-shaped

8 Labellum with distinctively coloured and shaped central

area (speculum) 30. Ophrys

1 Edit. D. M. Moore.

8 Labellum without speculum

9 Labellum directed upwards

10 Labellum shorter than outer perianth-segments; inner perianth-segments c. 1 /2as long as the outer

35. Hammarbya

10 Labellum about as long as outer perianth-segments; inner perianth-segments as long as or slightly shorter than the outer

11 Outer perianth-segments not more than 3 mm; labellum densely tuberculate beneath towards apex; plant with 2 pseudobulbs borne one above the other 34. Microstylis

11 Outer perianth-segments at least 5 mm; labellum not tuberculate towards apex; plant with 2 pseudobulbs joined by short horizontal stolon 33. Liparis

9 Labellum directed downwards

12 Labellum divided by a constriction into a concave basal part (hypochile) and a flat, downward- or forward-pointing distal part (epichile)

13 Plant with tubers; epichile pendent 29. Serapias

13 Plant with rhizomes or stolons; epichile not pendent 14 Outer perianth-segments not more than 4 mm

9. Goodyera

14 Outer perianth-segments at least 7 mm

15 Flowers patent or pendent, pedicellate, in a ± secund spike; column not longer than wide

2. Epipactis 15 Flowers suberect, sessile or subsessile, not in a secund spike; column longer than wide

3. Cephalanthera

12 Labellum not clearly divided by a constriction into hypochile and epichile

16 Flowers white, arranged in 1 -3 spiral rows or in a secund spike 8. Spiranthes

16 Flowers yellowish, greenish or purplish, neither arranged in spiral rows nor in a secund spike

17 Leaves about equalling stem, linear; labellum entire or shallowly lobed 14. Chamorchis 17 Leaves distinctly shorter than stem, oblong to linearlanceolate; labellum conspicuously lobed

18 Plant with rhizomes; labellum 2-lobed 7. Listera 18 Plant with 1 or 2 tubers; labellum 3-lobed, the median lobe sometimes 2-fid

19 Plant with 1 tuber at anthesis; median lobe of labellum entire 11. Herminium 19 Plant with 2 tubers at anthesis; median lobe of labellum deeply 2-fid 25. Aceras

5 Flowers with a spur

20 Labellum with median lobe much exceeding the lateral and spirally twisted

21 Bracts equalling or shorter than flowers; outer perianthsegments connivent with inner lateral to form a galea 26. Himantoglossum

21 Bracts exceeding flowers; outer perianth-segments erecto-

patent, not connivent to form a galea 27. Barlia 20 Labeilum entire or with median lobe not much exceeding the lateral and not spirally twisted

22 Labellum divided by a constriction into a concave basal part (hypochile) and a flat distal part (epichile)

3. Cephalanthera

22 Labellum not divided into hypochile and epichile

23 Labellum entire or crenulate

24 Spur not more than 2 mm 17. Nigritella

24 Spur more than 2 mm

25 Flowers greenish-white 13. Platanthcra

25 Flowers white or pink to purple or brownish, not greenish-white

26 Spur 25-30 mm 13. Platanthera

26 Spur less than 25 mm

27 Bracts membranous 24. Orchis

27 Lower bracts herbaceous 19. Dactylorhiz a

23 Labellum 3- or 5-lobed or 3-dentate at apex

28 Perianth-segments free, not forming a galea

29 Flowers yellowish-green; spur saccate 10. Gennaria

29 Flowers pinkish-lilac; spur cylindrical-conical 23. Traunsteinera

28 At least some perianth-segments connivent to form a galea

30 Spur more than 10 mm

31 Spur c. 1 mm wide

32 Labellum shallowly 3-lobed, without ridges at base; tubers palmately lobed 15. Gymnadenia

32 Labellum deeply 3-lobed, with 2 longitudinal ridges at base; tubers entire 28. Anacamptis

31 Spur more than 1 mm wide

33 All bracts membranous 24. Orchis

33 Lower bracts herbaceous 19. Dactylorhiza

30 Spur not more than 10 mm

34 Labellum 3-dentate at apex, the lateral teeth parallel and much longer than the median 18. Coeloglossum

34 Labellum 3- or 5-lobed, the lateral lobes not parallel

35 Lobes of labellum prolonged into long, filiform, ± spiral processes 21. Comperia

35 Lobes of labellum without long, filiform processes

36 All bracts membranous

37 Lateral lobes of labellum linear 22. Neotinea

37 Lateral lobes of labellum oblong, ovate or rhombic 24. Orchis

36 At least the lower bracts herbaceous

38 Outer perianth-segments connate almost to apex 20. Steveniella

38 Outer perianth-segments free, though sometimes connivent to form a galea

39 Perianth-segments at least 5 mm

40 Spike secund; lateral lobes of labellum linear- setaceous 12. Neottianthe

40 Spike not secund; lateral lobes of labellum oblong 19. Dactylorhiza

39 Perianth-segments not more than 3 mm

41 Spur 4-5 mm, as long as or slightly shorter than ovary; flower pinkish-lilac, purple or white 15. Gymnadenia

41 Spur not more than 2-5 mm, i - £ as long as ovary; flower yellowish- or greenish-white 16. Pseudorchis