58 ORCHIDACEAE 



Pollinia not produced into caudicles. 

 Pollinia granulose or powdery. 



Anthers operculate; leaves alternate. 



Green plants, with large leaves. 9. Serapias. 



Plant white, turning brownish; leaves reduced, scale-like. 



10. Ebxjrophtton. 

 Anthers not operculate. 



Leaves green, borne on the stem. 



Leaves alternate; spike mostly twisted. 11. IBIDIUM. 



Leaves 2, opposite; spike not twisted. 12. OpHRYS. 



Leaves usually white-reticulate, basal. 13. Peramium. 



Pollinia smooth or waxy. 



Plants with corms or soUd bulbs, rarely with coralloid roots; leaves not scale- 

 like. 

 Leaves unfolding before or with the flowers. 

 Lip flat; flowers racemed. 



Leaves caxillne; column short; pollinia clavate. 



14. MAL.\^XI3. 



Leaves basal; column elongated; pollinia globose. 



15. LIP.\RI3. 



Lip saccate; flower solitary. 16. Cytherea. 



Leaf 1, unfolding after the flowering time. 17. Aplectrum. 



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



18. Corallorrhiza . 



1. CRIOSANTHES Raf. R.oi's-head. Ram's-head L.\dies' Slipper. 



1. C. arietinum. 



2. CYPRIPEDIUM L. Ladies' Slipper. 



Leaves alternate: flowers solitary, terminal, or also several singly in the a.xils of the 

 upper leaves. 

 Sepals obovate to broadly obovate or oval, not longer than the lip; sterile stamen 

 elliptic-cordate. 1. C. passerinum. 



Sepals lanceolate, attenuate, often longer than the Up. 



Lip white, purple-veined; sterile stamen ovate or obovate. 2. C. monlanuni. 



Lip yellow; sterile stamen triangular, yellow and purple-spotted. 



Lip 2-2.5 cm. long, broader than deep; lower sepal narrower than the upper 

 one, exceeding the lip. 3. C. parviflorum. 



Lip 3-4 cm. long, deeper than broad ; lower sepal fully as broad as the upper 

 one or broader, usually shorter than the lip. 4. C. reganum. 



Leaves 2, opposite or nearly so; flowers usually several in a contracted bracted spike. 



5. C. Knightae. 



3. ORCHIS (Tourn.) L. Orchis. l. O. rotundi folia. 



4. COELOGLOSSUM Hartman. l. C. bracteatum. 



5. LYSIAS Salisb. 



Leaves orbiculai or rounded oval; spur sUghtly clavate at the apex. 1. L. orhiculata. 



Leaves oval or ovate; spur strongly clavate and curved at the apex. 2. L. Menziesii. 



6. LYSIELLA Rydb. l. L. obtusata. 



7. LIMNORCHIS Rydb. Bog Orchid. 



Lip more or less lanceolate, i. e., broad near the base. 



Flowers greenish or purpUsh; lip not rhombic at the base. 



Spur decidedly clavate, tliickeued and obtuse at the apex, shorter than tlie lip. 

 Petals purplish; spur only one-half to two-thirds the length of the lip, very 

 saccate. 

 Lip linear or nearly so, 5-7 mm. long; ovary slightly curved; spike usually 



elongated. 1. L. stricta. 



Lip lanceolate, fleshy, 4-5 mm. long; ovary stronglj' curved ; spike usually 

 short. 2. L. purpurascens. 



Petals greenish; spur almost equalling the lip. 3. L. viridiflora. 



Spur slender, scarcely tliickened at all towards the apex, often acutish, equal- 

 hng or slightly exceeding the lip; plant tall and stout; flowers comparatively 

 large; sepals 4-6 mm long. 4. L. media. 



Flowers white or nearly so; lip lanceolate, decidedly dilated, subrhombic at the base. 

 Spur only slightly if at all exceeding the lip. 



Spur usually shorter than the Up and clavate. 5. L. borealis. 



Spur equaUing or slightly exceeding the lip, slightly or not at all clavate. 



6. L. dilalata. 

 Spur from one-fourth to two-thirds longer than the lip. 7. L. leucostachys. 



Lip linear, i. e., not at all dilated at the base. 



Spur shorter than the lip, decidedly saccate. 1. L. slricta. 



Spur much exceeding the Up, filiform. 



Spike comparatively dense. 8. L. ensifolia. 



Spike very lax. 9. L. laxiflora. 



