KEY TO THE FAMILIES AND GENERA 



121 



, St. very short: Ivs. crowded, some sessile and 



submerged, others (except in Stratiotes) 



long-stalked, with a floating blade: apathes 



peduncled; placentae of 2 lamellte, strongly 



intruded, dividing the ovary more or less 



perfectly into 6 cells. 



B. Styles 3 ; stamens 3-9 3. Limnobium. 



JB. Styles 6, 2-fid. 



c. Stamens with 6 2-fid filaments, of which 



3 have 2 anthers and 3 have 1 anther. ... 4. HydrochaHs, 

 cc. Stamens 11-15 5. Stratiotea. 



183. ORCHIDACEiE.* 

 /. Summary of Tribes, 



A. Fertile stamens 2, with a broad shield- 

 shaped sterile one (staminodium) . . 1. Ctpripedium 

 iA. Fertile stamen 1, with no staminodium. [Tribe. 



B. Anther persistent; pollinia with basal 

 appendages. 

 c. The anther erect. 



D. Stigma flat, unappendaged 2. Serapiab Tribe. 



DD. Stigma with appendages 3. Habenaria Tribe. 



cc. The anthers placed obliquely 4. Satyrium Tribe. 



bb. Anther usually readily deciduous; 

 polhnia not appendaged or with 

 terminal ones. 

 C. Infl. terminal. 



D. Lf.-buds convolute. 



E. Lf.-blade not jointed to stalk. 



F. The ant her commonly 



much exceeding the beak 



of the column which is 



not distinctly cut. 



G. Lip without hypochil, 



usually spurless. 



H. St. short, with only 



1 or 2 Ivs 5. PoGONiA Tribe. 



HH. St. long, with many 



Ivs 6. Vanilla Tribe. 



GG. Lip with distinct hypo- 

 chil, which is often 



spurred 7. Cephal.\n-thera 



FF. The anther commonly [Tribe. 



about as long as the beak 

 of the column which 

 usually bears a sharp cut 

 or groove. 

 Q. PoUinia waxy or pow- 

 dery, not di\-ided. 



H. Lip turned down 8. Spiranthes Tribe. 



HH. Lip turned up 9. Cranichis Tribe. 



GO. PoUinia divided into dis- 

 tinct masses 10. Physurus Tribe. 



EE. Lf.-blade distinctly jointed to 

 the petiole. 

 F. Pollinia S: at. slender: fls. 

 usually with spurs or 



chins 11. Thunia Tribe. 



FF. Pollinia 4: st. a short pseu- 

 dobulb: fls. without spurs 



or chins 12. Ccelogtne Tribe. 



DD. Lf.-buds condupUcate. 



E. Sepals and petals about 

 equally developed, the lip 

 usually very conspicuous. 

 F. Lvs. usually not jointed: 



column footless 13. Liparis Tribe. 



FF. Lvs. usually jointed. 

 G. Nerves of lvs. 1. 



H. PoUinia 2-4. with very 



short stalks 14. Poltbtachya 



HH. PoUinia 4-8, with dis- [Tribe. 



tinct caudicles. 



I. Column-foot forming 



a chin with the 



lateral sepals or a 



short sac with the 



lip 15. Ponera Tribe. 



II. Column footless 16. Cattleya Tribe. 



GG. Nerves of lvs. several. . ..17. Sobralia Tribe. 

 EE. Sepals much more developed 



than the petals and Up 18. Pleurothallib 



cc. Infl. lateral, or on separate shoot. [Tribe. 



D. Lf.-buds convolute. 



E. St. slender or gradually 

 swollen. 

 F. PoUinia with caudicles but 



without stalks 19, Phajtjs Tribe. 



FT. PoUinia without caudicles 

 but with stalks. 

 G. Lip jointed to column- 

 foot or forming a spur [Tribe. 



with it 20. Ctrtopodium 



♦For explanation of orchid flowers and of terms, see the 

 article Orchids. 



GG. Lip not jointed, often 



with a distinct hjrpochil. 21. Catasetcm Tribe. 

 EE. St. a short distinct pseudo- 

 bulb, 

 p. Lip jointed to the column- 

 foot. 

 G. Callus-ridges lengthwise. .22. Lycaste Tribe. 

 GO. Callus-ridges transverse .23. Zyggpetalum 

 FF. Lip continuous with col- [Tribe. 



umn-foot 24. Gonqora Tribe. 



DD. Lf.-buds condupUcate. 



E. St. terminating its growth in 

 1 year. 

 F. Lip movably jointed to foot 

 of column. 

 G. Lvs. not strap-shaped: 

 pollinia unappendaged 

 or with either caudicles 

 or stipes, but not with 

 both. 

 H. Flowering st. arising 

 from near the apex 

 of the slender st. or 

 from the p3eudobulb.25. Dendrobitjm 

 HH. Flowering st. arising [Tribe. 

 under the pseudo- 

 bulb or at the base of 

 the St. 

 I. Pollinia without ap- 

 pendages 26. Bulbophyllum 



n. PolUnia with distinct [Tribe. 



stalks. 

 J. Pseudobulbs usu- 

 ally present: flow- 

 ering St. arising 

 lower than new 



growth 27. Maxillaria 



jj. Pseudobulbs usu- [Tribe. 



ally wanting: 

 flowering st. 

 arising higher 

 than new 



growth 28. Huntleya Tribe. 



GG. Lvs. strap-shaped; pol- 

 linia with broad cau- 

 dicles and stipes 29. Cymbidium Tribe. 



FF. Lip immovably united to 

 foot of column. 



G. Fls. with spurs 30. loNOPSis Tribe. 



GG. Fls. without spurs. 



H. The fls. narrow, not 



open 31. Ada Tribe. 



HH. The fls. wide, open. 

 I. Lip enrolled around 



the column 32. Trichopilla 



II. Lip not enrolled. [Tribe. 



J. The lip united to 

 column to the 



middle 33. Aspasia Tribe. 



JJ. The Up united 

 only to the base 



of the column. ..34. Odontoglossum 

 EE. St. increasing in length from [Tribe. 



year to year 35. Aerides Tribe. 



//. Key to the Tribes, 



1. Cypripedium Tribe. 



A. Fl. persistent, withering on the ovary: lf.- 

 buds convolute 1. Cypriped- 



AA. Fl. soon deciduous: lf.-buds condupUcate. [ium. 



B. Ovary 3-ceUed, the placentae central; 



mouth of Up with broad inturned margin. . 2. Pkragmoped- 

 EB. Ovary 1-ceUed, the placentse parietal; [Hum. 



mouth of Up usually with no broad 



inturned margins 3. Papkio- 



[pedilum. 



2. Serapias Tribe. 



A. Lip spurred. 



B. Sepals free 4. Orchis. 



BB. Sepals united into an arching hood 5. Galeorchis. 



A A. Lip spurless. 



B. PoUinia glands in a single sac 6. Serapias. 



BB. Pollinia glands separate, in 2 distinct sacs. . . 7. Ophrys. 



3. Habenaria Tribe. 



A. Lip adnate to column at base; stigma broad... 8. Cynorchis. 

 AA. Lip free; stigma slender 9. Habenaria. 



4. Satyrium Tribe 



Dorsal sepal helmet-shaped 10. Disa. 



