Chapter V — 75 — Types of Areas 



The term "relic" is commonly used in two different senses: taxo- 

 nomic and botanico-geographical. In the former it refers to taxo- 

 nomically isolated species belonging to ancient genera. Such species 

 may also be geographically isolated, i.e., they may have a relic area, 

 but they may also be widely distributed at the present time and, con- 

 sequently, not be relic in a geographical sense. A classical example of a 

 taxonomically isolated species having a relic area is the maidenhair 

 tree, Gingko biloba, while as an example of an ancient, taxonomically 

 isolated species having at the present time an extensive area that is 

 not relic we may take Loiseleuria procumbens. The latter is the sole 

 species in the genus Loiseleuria; nevertheless, it has an arctic-alpine, 

 for the most part post-glacial area. The use of the term "rehc" in a 

 botanico-geographical sense, on the other hand, always takes for 

 granted a relic area, and consequently a relic species in this sense is 

 always a remnant of an ancient flora, whether or not the genus to 

 which it belongs is taxonomically isolated or not. Only in the latter, 

 i.e., geographical, sense should the term "rehc" be employed, and then 

 there would at once be eliminated various confusions resulting from 

 its use. For remnants of ancient genera we might adopt the term pro- 

 posed by ScHROTER (1934) — "Restanz". The establishment of the 

 taxonomic antiquity of a species facilitates, of course, the estabhshment 

 of its relic nature. 



Differences of opinion as to the meaning of relic areas likewise arise 

 from a different evaluation of the age of a relic. Here, also, the age 

 of a relic should be understood not in a taxonomic but in a geographical 

 sense. That is, in establishing the age of a relic species one should 

 measure not from the date of its origin but from the date when it be- 

 came part of the flora under study. Thus, if a species has formed 

 part of a given flora since the Tertiary period, it will be a tertiary relic; 

 if, however, it became part of this flora only during the Ice Age, it 

 should be considered an Ice Age relic, irrespective of the fact that the 

 species itself arose in the Tertiary period in another flora not under 

 study. Consequently, the time a relic species has occupied its present 

 habitat is the main criterion for establishing its age. 



The date of the entrance of a species into the composition of any 

 given flora may be determined only approximately, except when paleo- 

 botanic data provide definite proof of the existence of a species on a 

 given territory uninterruptedly from the moment of the conversion of 

 its remnants into a fossil state up to the present day. Stoller (192 i) 

 maintains that only after such paleobotanic proofs of the uninter- 

 rupted habitation of a species may its relic character be accepted. 

 Theoretically this is correct, but in practice it is rarely adhered to, 

 since such proofs are possible only for an insignificant number of 

 species. Consequently, it is necessary to resort to botanico-geographi- 

 cal methods and with their aid to draw conclusions as to the relic 

 nature of a species. 



If by the term "relic" we understand a remnant of a former flora, 

 this does not mean that a relic species must necessarily occupy an 

 area more limited at the present time than originally. The area of a 

 relic may be comprised of a remnant or remnants of an extensive area 

 no longer in existence, or, on the other hand, it may consist of an 



