26 



NORMAN TAYLOR 



comparison of the figures thus obtained. The following table gives 

 a few of the percentages as determined by Raunkiaer for widely 

 separated areas. The percentages of the normal spectrum are given 

 for comparison. 



Percentages of Growth Forms in Biological Spectra, after Raunkaier 



Type of Growth-form 



Normal spectrum 6 17 20 9 27 3 1 13 



Baffin's Land 1 30 .Si 13 3 



Georgia 



Denmark I 3 3 3 50 11 II if 



Seychelles 10 23 24 6 12 3 2 16 



Libyan Desert 3 9 21 20 4 1 42 



JMG and 















MS 



MC 



N 



CH 



H 



G 



HH 



6 



17 



20 



9 



27 



3 



I 







I 



30 



51 



13 



3 



5 



7 



II 



4 



55 



4 



6 



1 



3 



3 



3 



50 



11 



11 



10 



23 



24 



6 



12 



3 



2 





3 



9 



21 



20 



4 



1 



These figures give some idea of the variation of climate implied 

 by the different growth-forms predominating in the different areas. 

 They also make more cogent the terms phanerophytic, hemicrypto- 

 phytic and chamaephytic as applied to climate. 



Raunkiaer has indicated three types of climate, as shown by his 

 study of growth-forms, namely a tropical area, an area of decreasing 

 warmth correlated with an increasing difference between winter 

 and summer temperatures and with a favorable distribution of preci- 

 pitation, and lastly a region with decidedly decreasing temperature, 

 or also, very commonly, with an unfavorable distribution of precipi- 

 tation, such as in deserts. The tropics are typical of the first of these 

 conditions, the eastern sides of North America and Asia are typical 

 of the second, and the arctic region and some deserts are characteristic 

 of the third type of climate, which may be seen also in our own South- 

 west. Many refinements of these rather gross outlines of climate 

 have been worked out, based on the so-called biochore, which is a line 

 with the same percentages of a definite growth-form, as found in 

 different parts of the continent. Such a study of the flora of North 

 America would be extremely interesting. It can be rightly based 

 only on complete percentages of growth-forms for different parts 

 of the country, and it is with the idea of supplying this for the local 

 flora area that the present paper has been written. 



In attempting to apply Raunkiaer's principles described above 

 and to get the biological spectrum of the flora near New York, I have 

 thrown out of the calculation all the 615 species of introduced weeds, 



