A QUANTITATIVE STUDY OF RAUNKIAER'S GROWTH- 

 FORMS AS ILLUSTRATED BY THE 400 COM- 

 MONEST SPECIES OF LONG ISLAND, N. Y. 



NORMAN TAYLOR 



Brooklyn Botanic Garden 



The value of sorting species of plants into different categories, 

 based on their growth-forms, has been pointed out so often that 

 there scarcely seems further need of going over the subject again. 

 The weakness of such a sorting and the percentages based on it, due 

 to the fact that species, not individual plants, are considered, is ob- 

 vious. Such percentages as have been published show not so much 

 an actual response to climatic factors, as they do the multiplicity of 

 forms that may have been developed. For most regions that is all 

 that can be done, as anything like a plant census of a given region is 

 usually impossible. Yet upon such a census, or some approximation 

 to it, there could be based percentages of different growth-forms that 

 reflect more accurately than any species percentage the actual climatic 

 response of vegetation to climate. 



The importance of getting, if possible, some growth-form per- 

 centages that should be quantitative rather than those based on 

 species only resulted in a study of the flora of Long Island, N. Y., 

 with this in view. The island is roughly 120 miles long and 12-16 

 miles wide and, excluding ferns and their allies, has about 1120 species 

 of native plants. It is diversified as to vegetation, as there are good- 

 sized areas of "scrub," mostly oak and Ericaceae, considerable de- 

 ciduous forest, some extensive "pine-barrens," salt marshes, a small 

 prairie, and the downs at Montauk and Shinnecock. 



In a general study of the flora and vegetation of the island, distri- 

 bution maps for each of the native species were made and have been 

 posted up for several years. Such maps indicate actual collections 

 represented by specimens in herbaria, field notes by the writer, all 

 published records of species and descriptions of different vegetative 

 areas by nearly all who have written about Long Island for the last 

 250 years. From Daniel Denton's History of New York, through 

 the period when numerous Quaker journals were issued, down to the 

 modern observations of professional botanists, these records have 

 been accumulated. The opportunity, therefore, of getting something 



486 



