236 



THE AMERICAN NATURALIST 



[Vol. XLI 



occasiouaily intergrade and perhaps can be regarded merely as 

 subspecies. I have found them growing together in closest 

 proximity. We have specimens of C. farvifloruin from Ontario, 

 British Columbia, New England, New York, New Jersey, Penn- 

 sylvania, Ohio, Indiana, Michigan, Wisconsin, Washington; 

 and of C. pubescens from New England, New York, Pennsylvania, 

 Ohio, Illinois, Wisconsin and Minnesota. The manuals extend 

 the reported occurrence of both plants to Georgia. Thus the 

 ranges of these two very closely allied kinds coincide over a very 

 wide extent of territory. No other form in the world stands 

 between them. 



The genus Calopogon is confined to the eastern half of the 

 United States (if we except the occurrence of C. pulchellus in 

 Cuba), and comprises four close species and a variety, or five 

 species. These species all come together and overlap in Florida. 

 One, C. pulchellus R. Br., ranges from Newfoundland to Florida, 

 Cuba, and Missouri, and geographically includes all the rest. C. 

 pallidus Chapm. ranges from North Carolina to Florida and 

 Alabama; C. parviforus Lindl. from North Carolina to Florida; 

 C. multiforus Lindl. is confined to Florida. Here, therefore, are 

 several pairs of cognate species not geographically separated. 



Pogonia vcriiciUata Nutt. and P. affinis Austin make a pair 

 of very nearly related yet distinct species. The former extends 

 from New England to Florida and west to Wisconsin and quite 

 surrounds the other, a very rare species occurring sporadically 

 in Vermont, Massachusetts, Connecticut, New York and New 

 Jersey. Here again geographic isolation is wanting. 



The conclusion from this examination of North American 

 Orchidacese is that cognate pairs of kinds w^ith uniform or widely 

 coincident ranges are too numerous to leave any force at all in 

 Jordan's law in its broad sense as regards this family in our flora. 

 If one member of each pair w^as derived from the other member, 

 or both were derived from a parent species, then, as jar aft the 

 geographic evidence goes, the new species may have originated 

 in the same district with the old one; i. e. without geographic isola- 



