GROWTH-FORMS OF FLORA OF NEW YORK AND VICINITY 29 



trated in the local flora. We find in the southern species about 12 

 per cent shrubs or trees, in the northern species only 5 per cent, well 

 illustrating the tendency for the woody plants to increase in size and 

 profusion as we travel southward. Among the small undershrubs there 

 appear to be none in the southern group, but over 8 per cent in the 

 northern, which is considerably over the percentage for this growth- 

 form in the whole flora. One of the most notable elements is the large 

 percentage of HH in the northern species (23 per cent) and the large 

 percentage of geophytes in the same group (24 per cent). Both these 

 figures are so much above those published for any other region, that 

 they may be open to the suspicion that other than climatic factors 

 have influenced them. This region in eastern North America has 

 never had this particular criterion of temperature response applied to 

 it, in fact I know of no region where such a large number of species as 

 our 1907 native plants have been used in making up the percentages as 

 published by Raunkiaer, Vahl, and Paulsen for other countries. On 

 the basis of the large numbers of species considered, and the obviously 

 temperate nature of our climate, it may be that the normal spectrum 

 as now understood is in need of revision. Certainly it seems to be 

 much too low in the case of geophytes and the aquatics, and too high 

 in the microphanerophytes. 



There are 19 northern species in the area, reaching their southerly 

 distribution outposts here, but found only at elevations, in excess of 

 1,000 ft., and most closely approximating an alpine habitat of any 

 of our native plants. Of course, percentages of growth-forms based 

 on such a small number of species are apt to be misleading, but as 

 illustrating a tendency they prove interesting. The following is a 

 list of such species : 



Growth-forms of Northern Species Reaching their Southerly Distribution 

 Outposts in the Area, but Found only at Elevations in Excess 



of 1000 Ft. 



Xyris montana = H Viola renifolia = G 



Juncus filiformis = G Moneses uniflora = G 



Spiranthes Romanzoffiana = G Ledum groenlandicum = N 



Mitella nuda = H Vaccinium Brittonii = N 



Fragaria canadensis = CH Adoxa Moschatellina = G 



Fragaria terra-novae = CH Valeriana uliginosa = G 



Rubus pergratus = H Solidago macrophylla = H 



Pyrus sitchensis = MS Aster junceus = H 



Viola nephrophylla = G Petasites palmatus = H 

 Viola Selkirkii = G 



