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TRANSACTIONS OF WAGNER 



VEGETATION OF SOUTH FLORIDA 



The actual number of species belonging to each growth form in the two 

 Florida districts is: 



The total number of phanerophytes in the Miami flora exceeds the total 

 number on the Florida keys by ten, but as percentages of the total growth 

 forms, the phanerophytes in the flora of the Florida keys are preponderant. 

 If we contrast these percentages with those of the growth forms of the pine- 

 barren region of New Jersey, we discover that the phanerophytes of that region 

 form 14.1 per cent., and the chamsephytes 10 per cent., while the hemicrypto- 

 phytes form 38 per cent, of the whole number of growth forms enumerated. 

 Physiognomically, the phanerophytes are dominant in the pine-barren region 

 of New Jersey, and they form the most striking part of the vegetation, while 

 in South Florida the undergrowth beneath the dominant trees belonging to 

 the phanerophytic and chamasphytic groups, while specifically more numerous, 

 is from the standpoint of actual numbers less in evidence and of secondary 

 importance. One specimen of a single species counts as much in fixing its 

 standing in the determination of the percentages of growth forms as 100,000 

 individuals of a species count. We have, therefore, this fact brought into 

 prominence that the growth forms of a region may be present in greater per- 

 centages of specific forms, but yet numerically, as to the actual number of 

 individuals of those types, of relatively little importance. In the pine-barren 

 region of New Jersey, we have a less number of species of phanerophytes (66) 

 than in the Miami region (178) and the Florida keys (168), but yet, numer- 

 ically, there are more phanerophytic individuals than in the two districts at 

 the southern end of the Florida peninsula. While Raunkiaer's spectra give 

 valuable information as to the percentages of growth forms, they do not give 

 any idea of the physiognomy of the vegetation, which must be expressed in 

 other ways. As an approximation to this estimate, we use the descriptive 

 terms of relative abundance: dominant, subdominant, abundant, occasional, 

 rare, very rare, local, locally abundant, local but occasional.* 



* For the significance of these terms consult Tansley, A . G.: An Ecological Study of a Cam- 

 bridgeshire Woodland. Journal Lirmaean Society, Botany, xl: 330-384, Jan., 1912. 



