2QO FLORA. 



Glands not enclosed in a pouch. 



Lip not fringed nor cut-toothed. 



Stem leafy ; anther-sacs mostly parallel. 



Valves of the anthers dilated at the base enclosing the glands below, 



4. Perularia. 

 Valves not dilated at the base. 



Glands surrounded by a thin membrane. 5. Cceloglossum. 

 Glands naked. 



Beak of the stigma with 2 or 3 appendages. 



6. Gytnnandeniopsts. 



Beak of the stigma not appendaged. 7. Limnorchis. 

 Stem scapiform ; leaves 1-2 basal ; anther-sacs divergent. 

 Basal leaves 2 ; ovary straight. 8. Lysias. 



Basal leaf i ; ovary arcuate. 9. Lysiella. 



Lip fringed or parted and cut-toothed. 10. BlepJiariglottis. 



Pollinia not produced into a caudicle (except apparently in No. 23). 

 Pollinia granulose or powdery. 



Flowers comparatively large, solitary or few ; anthers incumbent on a long 



column. 



Leaves not grass-like ; lip free. 

 Flowers terminal; lip crestedo 



Leaves alternate. n. Pogonia* 



Stem -leaves whorled. 12. Isotna. 



Flowers axillary; lip not crested. 13. l^riphora. 



Leaves grass-like. 



Flowers solitary, terminal ; lip adherent to the base of the column. 



14. Arethusa. 



Flowers racemose ; lip free. 15. Limodonan. 



Flowers small, numerous, in spikes or racemes; anthers erect, jointed to a 



short column. 



Anther operculate ; leaves broad, alternate. 16. Epipactis. 

 Anther not operculate. 



Leaves green, borne on the stem. 



Leaves alternate; spike mostly twisted. 17. Gyrostachys. 

 Leaves 2, opposite; spike not twisted. 18. Listera. 

 Leaves white-reticulated, basal. 19. Peramium. 



Pollinia smooth and waxy. 



Plants with corms or solid bulbs, rarely with coralloid roots ; leaves basal 



or cauline. 

 Leaves unfolding before or with the flowers. 



Leaf cauline ; lip ovate, or auricled at the base. 



20. Achroanthes* 

 Leaf or leaves basal. 



Leaves 2; lip flat ; flowers racemed. 21. Leptorchis. 

 Leaf i ; lip saccate ; flower solitary. 22. Calypso. 

 Leaf i, basal, unfolding after the flowering time. 



Flowers long-spurred ; lip 3-lobed. 23. Tipularia. 



Flowers not spurred ; lip 3-ridged. 24. Aplectrum. 



Plants with coralloid roots, bulbless ; the leaves reduced to scales. 

 Pollinia 4, in 2 pairs ; flowers gibbous or spurred. 



25. Corallorhiza. 

 Pollinia 8, united ; flowers not gibbous nor spurred. 



26. Hexalectris. 

 i. CYPRIPEDIUM L. 



Glandular-pubescent herbs, with leafy stems or scapes, and tufted roots of thick 

 fibres. Leaves large, broad, many-nerved. Flowers solitary or several, drooping 

 large, showy. Sepals spreading, separate, or 2 of them united under the lip. L-'p 

 a large" inflated sac. Column declined, bearing a sessile or stalked anther on each 

 side and a dilated petaloid sterile stamen above, which covers the summit of the 

 style. Pollinia granular, without a caudicle or glands. Stigma terminal, broad, 

 obscurely 3-lobed. [Name Greek, Venus' sock or buskin.] Alxrnt 40 species, 

 natives of temperate and tropical regions. Besides the following, some 5 others 

 occur in western North America. 



Sepals separate ; stem leafy, i-flowered. i. C. arietinum. 



Lateral sepals more or less united. 



Plant 2-leaved ; scape i -flowered. 2. C. acanle. 



Stem leafy to the top, i-several-flowered. 



Sepals and petals not longer than the lip, 3. C. reginae. 



