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AMERICAN CopE oF BoranicaL NOMENCLATURE 169 
CODE 
| Part I: PRINCIPLES. 
1. The primary object of formal nomenclature in systematic biol- 
ogy is to secure stability, uniformity and convenience in the 
designation of plants and animals. 
2. Botanical nomenclature is treated as beginning with the general 
application of binomial names of plants (Linnaeus’ Species 
Plantarum, 1753). 
3. Priority of publication is a fundamental principle of botanical 
nomenclature. Two groups of the same category cannot 
bear the same name. 
Norte. — Previous use of a name in zodlogy does not preclude its use in 
botany ; but the proposal of such a name should be avoided. 
4. The application of a name is determined i reference to its 
nomenclatorial type. 
Part II. Canons. 
Section I. Categories of Classification, — 
Canon 1. Connected or coherent groups of individuals are termed 
species. 
Canon 2. Species are grouped into genera; genera into tribes; 
tribes into families ; families into orders ; orders into classes ; 
classes into divisions. 
Canon 3. When additional categories are necessary for the con- 
venient presentation of relationships, they are to be obtained 
by the recognition of intermediate groups, the names of which 
are formed by prefixing sub- to the names of the above 
principal categories. 
EXAMPLES. — Subspecies, subgenus, subfamily, suborder. 
Canon 4. Other terms, such as group, section, series, and branch, 
may be used for more convenient temporary arrangement 
under the above categories, but their names are to have no 
validity in formal taxonomy. 
Nore. — The term variety is relegated to horticultural usage. 
Section Il. Formation of Names. 
Canon 5. Specific and subspecific names consist of Latin or 
Latinized adjectives or substantives, the latter being either 
nominatives in apposition or genitives. 
