3. Calypso. Leaf solitary. Flower large, solitary. Lip saccate.

[++][++] A single green autumnal leaf; otherwise mainly brownish or purplish.

4. Tipularia. Raceme many-flowered; flowers small, greenish; lip 3-lobed.

5. Aplectrum. Raceme loose; flowers rather large; lip 3-ridged, not spurred or saccate.

[*][*] Leafless, with coralloid roots; whole plant brownish or yellowish; flowers racemose.

6. Corallorhiza. Pollinia 4, in 2 pairs. Flower gibbous or somewhat spurred, and lip with 1–3 ridges; sepals and petals 1–3-nerved.

7. Hexalectris. Pollinia 8, united. Flower not gibbous; sepals and petals several-nerved; lip with 5–6 ridges.

Tribe II. NEOTTIEÆ. Anthers erect upon the back of the column at the summit, or terminal and opercular. Pollinia granular or powdery, more or less cohering in 2 or 4 delicate masses, and attached at the apex to the beak of the stigma.

[*] Anthers without operculum, erect upon the back of the short column. Flowers small, in spikes or racemes.

8. Listera. Stem from a fibrous root, 2-foliate. Lip flat, 2-lobed.