General description:- Perennial herbs with rhizomes, vertical stock or tuberous roots, terrestrial, sometimes obtaining nutrition from decaying matter (saprophytic), usually with symbiotic fungi in or on the roots (mycorrhiza).
Stems:- Sometimes swollen at base to form pseudobulbs.
Leaves:- Entire, spirally arranged or in two opposite rows, one on each side of the stem (distichous), rarely subopposite, reduced to scales or sheaths in saprophytes.
Flowers:- Inflorescence a spike or raceme. Flowers zygomorphic, the sepals, petals and stamens apparently inserted higher than the ovary (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 stem (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 stalkless (sessile) or short-stalked (subsessile), 2-celled (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-like 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, splitting open to release the seeds (dehiscing) by 3 or 6 longitudinal slits; seeds numerous, minute, with undifferentiated embryo and no endosperm.
ANACAMPTIS
Tubers:- Usually 2, ovoid or subglobose, entire.
Stem:- With numerous leaves.
Flowers:- In a dense spike. Outer lateral perianth-segments patent, the outer median connivent with the inner lateral to form a galea. Labellum deeply 3-lobed, with 2 longitudinal ridges at the base. Spur long, directed downwards. Column short. Rostellum small. Viscidium solitary, transversely elongate, bearing 2 pollinia; bursicle simple.
Key features:-
1) Labellum deeply 3-lobed, with 2 longitudinal ridges at base.
2) Tubers entire.
CEPHALANTHERA
General description:- Plants with short, creeping rhizome.
Stem:- Leafy
Flowers:- Few, large, suberect, stemless or nearly so (sessile or subsessile), in a lax spike, scentless. Perianth-segments similar, usually uniting distally (connivent) to give bell-shaped (campanulate) flowers. Labellum constricted between the suberect concave basal part (hypochile) and the forward-directed distal part (epichile) which has a recurved apex and 3-9 interrupted longitudinal ridges above; spur absent or very short. Column long, erect. Rostellum absent. Viscidia absent; bursicles absent.
1) Flowers suberect, sessile or subsessile, not in a secund spike; column longer than wide.
2) Labellum entire or with median lobe not much exceeding the lateral and not spirally twisted
3) Labellum divided by a constriction into a concave basal part (hypochile) and a flat distal part (epichile).
DACTYLORHIZA
Tubers:- 2-3, usually palmately 2- to 5-fid, more or less elongated at the apex, rarely oblong-cylindrical and shallowly 2(-4)-fid.
Flowers:- Perianth-segments free, equal or the inner smaller, patent or deflexed, rarely convergent. Labellum pointing upwards at a slight angle from the vertical (porrect) or slightly decurved. Spur present. Lower bracts herbaceous. Rostellum 3-lobed, the middle lobe short, lamelliform. Viscidia in one simple bursicle.
Key features:-
1) Lower bracts herbaceous.
2) Spike not secund.
3) Lateral lobes of the labellum oblong.
EPIPACTIS
General description:- Plants with horizontal or vertical rhizome and numerous fleshy roots.
Stem:- Leafy.
Flowers:- Pedicellate, patent or pendent, in more or less secund spikes. Perianth-segments free, patent or connivent, the inner similar to the outer but smaller. Labellum with concave or cupuliform basal part (hypochile) separated by narrow joint or fold from the flat, forward-directed distal part (epichile), with basal tubercles or ridges; spur absent. Column short. Rostellum usually large and globose, sometimes absent. Viscidia absent; bursicles absent.
Key features:-
1) Outer perianth-segments at least 7 mm.
2) Flowers patent or pendent, pedicellate, in a ± secund spike; column not longer than wide.
HIMANTOGLOSSUM
Tubers:- 2, ovoid to subglobose, entire.
Stem:- With numerous leaves, clothed with brownish fibres at base.
Flowers:- In a long spike. Bracts equalling or shorter than flowers. Outer perianth-segments uniting distally (connivent) with inner lateral to form a helmet-shaped structure (galea). Labellum 3-lobed, much exceeding other perianth-segments, the middle lobe much exceeding the lateral and spirally twisted. Spur present. Column rather short. Rostellum prominent, beak-like. Viscidium solitary, hemispherical or ellipsoid, bearing 2 pollinia, bursicle simple.
LIMODORUM
General description:- Violet saprophytes (plants without chlorophyll which live on humus) with short rhizome.
Stem:- Clothed with scale-like sheaths. Green leaves absent.
Flowers:- In an erect, spike-like raceme. Perianth-segments free, patent. Labellum entire. Spur long, slender, curved upwards. Column long. Viscidium solitary; bursicles absent.
Key features:-
1) Plant without green leaves
2) Spur long, slender
3) Labellum entire, directed downwards.
NEOTINEA
Tubers:- Ellipsoid, entire.
Leaves:- Basal 2-4. Perianth-segments more or less equal, connivent into a galea. Labellum scarcely longer than other perianth-segments, 3-lobed. Spur very short. Stigmas approximated at base, diverging above in the form of a V. Viscidia distinct, enclosed in a 2-lobed bursicle.
Key features:-
1) Lobes of labellum without long, filiform processes.
2) All bracts membranous.
3) Lateral lobes of labellum linear.
NEOTTIA
General description:- Yellowish-brown saprophytes, with short, creeping rhizome covered with thick, fleshy roots to form a nest-like mass.
Stem:- Covered with brownish scales.
Leaves:- Green leaves absent.
Flowers:- Numerous, in a spike-like raceme, fragrant. Perianth-segments subequal or the inner somewhat shorter, somewhat convergent into an open galea. Labellum saccate at base, 2-lobed distally; spur absent. Column long, slender. Rostellum wide, flat. Viscidia absent; bursicles absent.
1) Spur very short or absent.
2) Stem with numerous scales.
3) Labellum c. twice as long as the other perianth-segments.
OPHRYS
General description:- Tubers 2(-3), globose or ovoid, entire.
Leaves:- Usually in a basal rosette, sometimes also present on stem.
Flowers:- Perianth-segments more or less spreading (patent), unequal; outer oblong or ovate, obtuse; inner lateral smaller, often hairy.The lowest petal (labellum) entire to 3-lobed, often convex and pouch-like (gibbous), sometimes with an apical appendage which is often deflexed, hairless (glabrous) or velvety (velutinous), variably marked, with usually glabrous central area (speculum); spur absent. Rostellum minute. Viscidia in 2 simple bursicles.
Key features:-
1) Labellum neither inflated nor slipper-shaped; with distinctively coloured and shaped central area (speculum).
ORCHIS
Tubers:- 2-3, globose to ellipsoid, entire.
Flowers:- Perianth-segments free, equal, or sometimes the inner smaller, all convergent into a helmet-shaped structure (galea) or the outer spreading (patent) and deflexed. Labellum pointing upwards at a slight angle from the vertical (porrect) or slightly decurved, entire to 3-lobed, hairless (glabrous) or covered with small nipple-like projections (papillose). Spur present. Bracts membranous. Rostellum 3-lobed, the middle lobe short, with thin plates stacked on top or next to each other (lamelliform). Viscidia in a 2-lobed bursicle.
Key features:-
1) Spur less than 25 mm.
2) Bracts membranous.
3) Spur more than 1 mm wide.
4) Lateral lobes of labellum oblong, ovate or rhombic.
SERAPIAS
Tubers:- 2-5, ovoid to globose, entire.
Leaves:- Narrow, canaliculate, acute, entire, usually shiny.
Flowers:- In a spike. Outer perianth-segments ovate-lanceolate, acute, partially connate, connivent with the linear-lanceolate, acuminate inner lateral to form a galea. Labellum large, constricted into basal hypochile, with two indistinct lateral lobes, and prominent, pendent epichile. Spur absent. Column long. Rostellum small. Viscidium solitary; bursicle simple.
Key features:-
1) Labellum divided by a constriction into a concave basal part (hypochile) and a flat, downward- or forward-pointing distal part (epichile).
2) Plant with tubers.
3) Epichile pendent.
All species appear to hybridize readily with each other and with species of Anacamptis, Dactylorhiza, Ophrys and Orchis.
SPIRANTHES
Roots:- Fleshy, more or less tuberous.
Flowers:- Spike-axis twisted, so that flowers are arranged in one or more spiral rows. Perianth-segments subequal, free or variously united (connate) or uniting distally (connivent). Flowers fragrant, bent, knee-style (geniculate) or bow-like (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.
Key features:-
1) Labellum not clearly divided by a constriction into hypochile and epichile.
2) Flowers white, arranged in 1-3 spiral rows or in a secund spike.