ORCHIDACEiE 



Flora of the Northern States and Canada, for which Dr. Ryd- 

 berg prepared a revision of the Orchidaceae. In this work eigh- 

 teen species are admitted which were formerly included by Gray, 

 and Britton and Brown, in the genus Habenaria. Dr. Rydberg 

 has distributed these species among seven genera, of which three 

 by him are newly established. The characters on which he relies 

 for the distinctiveness of these genera are not clearly drawn, so 

 that it is difficult to discuss their claim for recognition, and in 

 his key he makes use of differences which would seem to be 

 rather specific than generic. 



Perfect agreement as to the final treatment of Habenaria is 

 hardly to be expected, but it is a fair question to ask if the rea- 

 sons which influenced Bentham, Gray and Torrey are not as valid 

 to-day as they were thirty years ago, and if, on the whole, they 

 were not pretty good reasons. Furthermore, it is fair to ask if the 

 host of species described since 1840 has thrown new light on the 

 subject which makes invalid the reasoning of Bentham in the 

 Journal of the Linncean Society. With regard to Bentham's ar- 

 gument it may be said that nothing so convincing has been put 

 forth by those botanists who have disagreed with him. 



The following from Bentham's notes on orchids will show 

 clearly the basis for the treatment of Habenaria in the Genera 

 Plantarum. 



"jyra6^7iana,Willd., is now a vast cosmopolitan, and in many 

 respects polymorphous, genus, of which there are about three 

 hundred and fifty species in the Kew herbarium, and perhaps 

 fifty more, already published, are not there represented. The dif- 

 ferences observed in the anther-cells, in the stigma, and in va- 

 rious appendages to parts of the flower are so great that numer- 

 ous attempts have been made to dismember it; but the single 

 characters assigned have all proved either so variable from spe- 



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