ORCHIDACEAE 91 



Glands of the stigmas naked. 

 Beak of the stigma with 2 or 3 appendages. 



5. Gymnadeniopsis. 

 Beak of the stigma not appendaged. 6. Limnorchis. 

 Anther sacs divergent : stems scape-like. 7. Lysias. 

 *"* Lip or its lobes fringed or laciniate. 8. Blephariglottis. 



b. Lip spurless, or if with a spur, this merely sac-like : anther adnate to 

 the back of the column : sacs approximate. 

 Lip flat, at least not saccate. 

 Stems with alternate leaves, these often scale-like : lip neither cleft 



nor parted. 9. Gyrostachys. 



Stems with opposite leaves : lip 2-cleft or 2-parted. 



10. LiSTERA. 



Lip sac-like. 11. Peramium. 



B. Anther attached to the ape.x of the column like a lid, deciduous. 

 Pollen in loose powdery masses. 



Scapose plants : leaves basal or wanting. 

 Leaves basal, sheathing the scape : bracts alternate : column winged 



at the apex. 12. Limodorum. 



Leaves wanting or mere basal scales : bracts whorled at the top of the 

 scape. 13. IsoTRiA. 



Caulescent plants. 



Column club-shaped or very short, wingless : pollen masses 2 or 2- 

 parted. 

 Flowers normally solitary, terminal : lip crested. 



14. POGONIA. 



Flowers axillary, in few-flowered racemes : lip not crested. 



15. Triphora. 

 Column dilated above, petal-like : pollen masses 4. 



16. Arethusa. 

 Pollen in waxy masses. 



Pollen masses without either elastic connecting tissue or stalks. 

 Stems bearing normal leaves. 



Leaf sheathing the scape to near the middle : column minute, 



2-toothed at the apex. 17. Achroanthes. 



Leaves barely, sheathing the scapes : column elongated, incurved, 

 margined above. 18. Leptorchis. 



Stems bearing clasping or sheathing scales. 



Rootstocks coral-like : lips with a short spur adnate to the ovary, 



proper leaves none. 19. Corallorhiza. 



Rootstock corm-like : lip spurless : proper leaf solitar^^ absent dur- 

 ing anthesis. 20. Aplectrum. 

 Pollen masses with connecting tissue and stalks. 



21. Tipularia. 



1. CYPRIPEDIUM L. 



Scapose : leaves 2, basal : lip with a fissure down the front : sterile stamen 



glandular-pubescent : stigma broadest at the apex. i. C. acavle. 



Caulescent : leaves several : lip with a rounded opening : sterile stamens 

 glabrous : stigma broadest at the base. 

 Lip longer than the sepals and the lateral petals. 2. C. reginae. 



Lip shorter than the sepals and lateral petals or about as long. 



Sterile stamen lanceolate : lip white. 3. C. candidum. 



Sterile stamen triangular : lip yellow. 



Lip bright yellow, 1.5-3 cm. long: stigma acute. 4. C. pa7viflorum. 



Lip pale 3'ellow, 3.5-5 cm. long : stigma obtuse. 5. C. hirsjilnni. 



