HORTICULTURAL SOCIETY OF NEW YORK. 



force to this is the fact that the epiphytic orchids of the United States are 

 confined to the Gulf States. Terrestrial orchids, as a rule, have thin leaves, 

 their habitat not making so precarious their w^ater supply. 



Orchids are local in distribution, extremely so in some cases. Few 

 gerera are common to both the Old World and the New, or if they are thus 

 common they follow a zonal distribution. The genus Cypripedium may, 

 perhaps, be cited as an exception to this, but it really may be taken as a 

 good example of the point in view. This genus, as understood by botanists 

 for many years, has now been separated into four genera by the best authori- 

 ties of the present day. These four are: Selenipedium, Cypripedium, 

 Phragmipedium, and Paphiopedilum. These seggregates have been made 

 on characters found in the ovary, in the vernation of the leaves, and in the 

 relative position of the parts of the perianth. This may be summarized in 

 the following key: 

 Vernation convolute; perianth withering, persistent in fruit. 



Ovary 3-celled; seed subglobose, the seed-coat crusty. 



Ovary i-celled; seed elongated, the seed-coat thin. 



Selenipedium. 



Cyripedium. 

 Vernation conduplicate; perianth deciduous. 



Ovary 3-celled; aestivation of sepals valvate; margin of sac of lip 



broadly involute or infolded. 



Phragmipedium. 



Ovary i-celled; aestivation of sepals imbricated; margin of sac of lip 



upright, or but slightly incurved or recurved, 



Paphiopedilum. 



Thus by dividing, we not only get more natural genera but conform 

 with what we know about the local distribution of orchids. Instead of a 

 world-wide group of about 90 species, we have: 



Selenipedium, with 3 species, known only from Central America to 

 Brazil. 



Cypripedium, in a restricted sense, with 28 species, zonal in distribution, 

 from North America, Europe and Asia. 



Phragmipedium, with 11 species, in tropical America only. 



Paphiopedilum, with 46 species, from the Old World only, topical 

 Asia, Malayan region, Philippines, etc. 



The lecture was illustrated by a series of lantern slides, emphasizing the 

 points made by the speaker. A large proportion of these were colored 

 slides made by Mrs. Van Brunt, who kindly loaned them for the occasion. 

 These colored slides were used especially to illustrate the genera peculiar 

 to the Old World and the New, and such as were of zonal distribution. 



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