INTRODUCTION. 



ALLEGHENIAN SPECIES. The Allegheny mountains, from their pe- 

 culiar position, their densely wooded character, the amount of moisture 

 condensing on them, are the home, especially in their southern section, 

 of a large number of species peculiar to their slopes or summits. Our 

 Flora also has its list of those which may be called Alleghenian, small 

 in proportion to the less distinctive character and lower elevation of the 

 Pennsylvanian ranges. We include the following in this list : 

 Dicentra Exitnia, Aster concinmis. 



Ilex mollis, Calamagrostis Porteri. 



The following are also characteristically Alleghenian, although occa- 

 sionally found in the mountains of New York and New England, or in 

 districts allied to the Allegheny system : 



Ilex monticola,) Carex lurida % var. gracilis y 



Rhododendron maximum, Carex ccstivalis, 



Aspleniuni montanum. 



The only one of the nine plants mentioned which descends into the 

 valley proper is the Rhododendron, which is less distinctively Alleghe- 

 nian than the others. On the other hand, the earlier list of common plants 

 mentioned, which give character to this region, and distinguish it from 

 the districts adjoining north and west, are mostly plants of the valley 

 or of the lower slopes of the mountains. 



SPECIAL AFFINITIES WITH LARGER FLORAS. 



Turning now to a consideration of those species which have their cen- 

 ters of development in regions more or less remote from our valley and 

 plateau, and which extend to this region, but no farther, we find facts 

 of considerable interest. 



THE ATLANTIC SLOPE. There are a certain number of Atlantic slope 

 species whose western limits of distribution are within our borders. We 

 have noted the following : 



Lechea thymifolia, *Orontinm aquaticum, 



Solidago puberuhi) Calamagrostis Nuttallii^ 



Aster raduldj Lycopodium inundatum, 



var. Bigelovii. 



*The "Golden Club," Orontium aquaticum, growing in several of our ponds, 

 deserves a passing notice, as it may have been introduced here by the Indians. 

 Kalm ("Travels in Nor. America," II., p. 110-115) says its seeds are used as food 

 by the Indians, who call it Taiv-kcc. Brinton ("Lenni Lenape and their Legends," 

 p. 50) says "the Delaware Indians" (the former occupants of the Wyoming Valley 

 and also of the Atlantic coast regions), "collected for food the seeds of the Golden 

 Club, common in the pools along the Creeks." In their migrations back and forth 

 they may have transplanted this food plant to the inland ponds. 



