CLASSIFICATION AND NOMENCLATURE 137 



impossible to designate each formation or succession by a 

 single Greek or Latin term, as habitats of the same char- 

 acter will show in different parts of the world a vegetation 

 taxonomically very different. It may some day be possible 

 to use a binomial or trinomial for this purpose, somewhat 

 after the fashion of taxonomy, in which the habitat name 

 will represent the generic idea as applied to formations, and 

 a term drawn from the floristic impress the specific idea. 

 Such an attempt would be futile or valueless at the present 

 time: it could not possibly meet with success until there is 

 more uniformity in the concept of the formation, and until 

 there has been much accurate and thorough investigation of 

 actual formations, a task as yet barely begun. At present, it 

 seems most feasible as well as scientific, to designate all for- 

 mations occupying similar habitats by a name drawn from the 

 character of the latter, such as a meadow formation, poium, a 

 a forest formation, hylium, a desert formation, eremium, etc. 

 A particular formation is best designated by using the 

 generic name of one or two of its most important species in 

 conjunction with its habitat term, as Spartlna-Elyrmis-poium, 

 Picea-Pinus-hylium, Cereus- Yucca- eremium, etc. Apparently 

 a somewhat similar nomenclature is adapted to successions. 

 The cause which produces a new habitat may well furnish 

 the basis for the name of the general groups of successions, 

 as pyrium (literally, a place or a habitat burned over), a 

 burn succession, tribium, an erosion succession, etc. A burn 

 succession consists of a sequence of certain formations in 

 one part of the world, and of a series of quite different ones, 

 floristically, in another. A particular burn succession 

 should be designated by using the names of a characteristic 

 facies of the initial and ultimate stages in connection with 

 the general term, e. g., Bryum-Picea-pyrium, etc. A tri- 

 nomial constructed in this way represents the desirable 

 mean between definition and brevity. Greater definiteness 

 is possible only at the expense of brevity, while to shorten 

 the name would entirely destroy its precision. The follow- 



'Clements, F. E. A System of Nomenclature for Phytogeography. 

 Engler31:b5 1903. 



