(7) Hemicryptophytes: Plants with perennial shoots and 

 buds close to the surface, often covered with litter, such 

 as bunchgrasses and many forbs (Figure 1-2) 



(8) Chamaephytes: Plants with buds located from the 

 ground surface to 25 cm above it, such as buffalograss 

 and white clover (Figure 1-13) 



(9) Phanerophytes: Shrubs, trees, and vines with buds 

 located on upright shoots at least 25 cm above the sur- 

 face (Figures 2-3 and 3-2) 



(10) Epiphytes: Plants growing on other plants (Figure 1-25) 



Most of these classes have been subdivided. 



All the species in a region or in a community can be classified 

 into these classes and the ratio expressed in numbers or percent- 

 ages, forming a floristic biological spectrum. This classification 

 is very useful in comparing communities. For example, grasslands 

 are usually rich in hemicryptophytes, tropical deserts in thero- 

 phytes, and arctic and alpine regions in chamaephytes and 

 hemicryp*^ophytes. In comparing communities, however, the 

 number of species is less satisfactory as a basis for establishing a 

 vegetational spectrum than frequency points, because the former 

 is based on the mere presence of the species in a community, while 

 the frequency-point spectrum is based on the sum of the fre- 

 quencies in each of the life-form classes. Relative cover may also 

 be used in determining the vegetational spectrum. The advan- 

 tage of the frequency method was demonstrated in hardwood 

 forests in Minnesota where Carex pennsylvanica occurred in 94 

 quadrats out of a total of 100 in 10 stands, and since it is a 

 cryptophyte it contributed 94 points to this class; but Clintonia 

 borealis, occurring in only 3 quadrats, contributed only 3 points 

 to the total of 97 points in this class. In the species-presence list, 



94 



The ConrnmiExiity 



