KEY TO THE FAMILIES AND GENERA 



121 



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

 submerged , others (except in Stratiotes ) 

 long-stalked, with a floating blade: spathes 

 peduncled: placentae of 2 lamellse, strongly 

 intruded, dividing the ovary more or lesa 

 perfectly into 6 cells. 



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



BB. Styles 6, 2-fid. 



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



3 have 2 anthers and 3 have 1 anther 4. Hydrocharis. 



cc. Stamens 11-15 .' 5. Stratiotes. 



183. ORCHIDACE^E.* 

 7. Summary of Tribes. 



A. Fertile stamens 2, with a broad shield- 

 shaped sterile one (staminodium) . . 1. CYPRIPEDHJM 

 AA. Fertile stamen 1, with no staminodium. [TRIBE. 



B. Anther persistent; pollinia with basal 

 ' appendages. 

 c. The anther erect. 



D. Stigma flat, unappendaged 2. SERAPIAS TRIBE. 



DD. Stigma with appendages 3. HABENARIA TRIBE. 



cc. The anthers placed obliquely 4. SATYRIUM TRIBE. 



BB. Anther usually readily deciduous; 

 pollinia not appendaged or with 

 terminal ones. 

 c. Infl. terminal. 



D. Lf.-buds convolute. 



E. Lf.-blade not jointed to stalk. 



F. The anther commonly 



much exceeding the beak 



of the column which is 



not distinctly cut. 



o. 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. 



GO. Lip with distinct hypo- 

 chil, which is often 



spurred 7. CEPHALANTHERA 



FF. The [anther commonly [TRIBE. 



about as long as the beak 

 of the column which 

 usually bears a sharp cut 

 or groove. 



Q. Pollinia waxy or pow- 

 dery, not divided. 



H. Lip turned down 8. SPIRANTHES TRIBE. 



HH. Lip turned up 9. CRANICHIS TRIBE. 



GO. Pollinic divided into dis- 

 tinct masses 10. PHYSURUS TRIBE. 



EE. Lf.-blade distinctly jointed to 



the petiole. 



F. Pollinia 8: st. slender: fls. 

 usually with spurs or 



chins 11. THTJNIA TRIBE. 



FF. Pollinia 4: st. a short pseu- 

 dobulb: fls. without spurs 



or chins 12. CGSLOGYNE TRIBE. 



DD. Lf.-buds conduplicate. 



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 Ivs. 1. 



H. Pollinia 2-4, with very 



short stalks 14. POLTBTACHYA 



HH. Pollinia 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. PONEHA TRIBE. 



n. Column footless 16. CATTLEYA TRIBE. 



OG. Nerves of Ivs. several 17. SOBRALIA TRIBE. 



EE. Sepals much more developed 



than the petals and lip 18. PLEUROTHALLIS 



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



D. Lf.-buds convolute. 



E. St. slender or gradually 



swollen. 

 F. Pollinia with caudicles but 



without stalks 19. PHAJUS TRIBE. 



FF. Pollinia without caudicles 



but with stalks. 

 G. lap jointed to column- 

 foot or forming a spur [TRIBE. 



with it 20. CYRTOPODIUM 



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

 article Orchids. 



GO. Lip not jointed, often 



with a distinct hypochil. 21. CATABETTJM TRIBE. 

 EE. St. a short distinct pseudo- 

 bulb. 



F. Lip jointed to the column- 

 foot. 



o. Callus-ridges length wise.. 22. LYCASTE TRIBE. 

 GG. Callus-ridges transverse .23. ZYGOPETALUM 

 FF. lap continuous with col- (TRIBE. 



umn-foot 24. GONGOBA TRIBE. 



DD. Lf.-buds conduplicate. 



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 pseudobulb.25. DENDROBITJM 

 BH. Flowering st. arising [TRIBE. 



under the pseudo- 

 bulb or at the base of 

 the st. 



I. Pollinia without ap- 

 pendages 26. BULBOPHYLLUM 



ii. Pollinia with distinct [TRIBE. 



stalks. 



j. Pseudobulbs usu- 

 ally present: flow- 

 ering st. arising 

 lower than new 



growth 27. MAXILLARIA 



33. Pseudobulbs usu- [TRIBE. 



ally wanting: 

 flowering st. 

 arising higher 

 than new 



growth 28. HUNT-LET A 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. IONOPSIS 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. TRICHOPILIA 



ii. Lip not enrolled. [TRIBE. 



j. The lip united to 

 column to the 



middle 33. ASPASIA TRIBE. 



jj. The lip united 

 only to the base 



of the column. ..34. ODONTOGI.OSSUM 

 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 conv9lute 1. Cypriped- 



AA. Fl. soon deciduous: If.-buds conduplicate. [turn. 



B. Ovary 3-celled, the placentae central; 



mouth of lip with broad inturned margin. . 2. Phragmoped- 

 BB. Ovary 1 -celled, the placenta parietal: [Hunt. 



mouth of Up usually with no broad 



inturned margins 3. Paphio- 



[pedilum. 



2. Serapias Tribe. 



A. Lip spurred. 



B. Sepals free 4. Orchis, 



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



AA. Lip spurless. 



B. Pollinia 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. 



