. International rules of Botanical Nomenclature.
Chapter I. General co n s id e ra tio n s an d le a d in g princ iples.
Art. 1. Natural history can make no progress without a regular system of
nomenclature, which is recognized and used by the great majority of naturalists in
all countries.
Art. 2. The prescriptions which govern the exact system of botanical nomenclature
are divided into principles, rules and recommendations. The principles (art.
1—9, 10—14 and 15 — 18) are the foundation of the rules and recommendations.
The rules (art. 10—58), destined to put in order the nomenclature which the past has
bequeathed to us, and to form the basis for the future, are always retroactive: names
or forms of nomenclature which are contrary to a rule cannot be maintained. Recommendations
bear on secondary points, their object being to ensure for the future a
greater uniformity and clearness in nomenclature: names or forms of nomenclature
contrary to a recommendation are not a model to copy, but cannot be rejected.
Art. 3. The rules of nomenclature should neither be arbitrary nor imposed
by authority. They must be simple and founded on considerations clear and forcible
enough for everyone to comprehend and be disposed to accept.
Art. 4. The essential points in nomenclature are: 1. to aim at fixity of
names; 2. to avoid or to reject the use of forms and names which may cause error
or ambiguity or throw science into confusion.
Next in importance is the avoidance of all useless creation of names.
Other considerations, such as absolute grammatical correctness, regularity or
euphony of names, more or less prevailing custom, respect for persons, etc., notwithstanding
their undeniable importance are relatively accessory.
Art. 5. No custom contrary to rule can be upheld if it leads to confusion
or error. When a custom offers no serious inconvenience of this kind, it may be a
ground for exceptions which we must however abstain from extending or copying.
Finally in the absence of rule, or where the consequences of rules are doubtful,
established custom becomes law.
Art. 6. The principles and forms of nomenclature should be as similar as
possible in botany and in zoology; but botanical nomenclature is entirely independent
of zoological nomenclature.
Art. 7. Scientific names are in latin for all groups. When taken from
another language, a latin termination is given them, except in cases sanctioned by
custom. If translated into a modern language, it is desirable that they should preserve
as great a resemblance as possible to the original latin names.
Art. 8. Nomenclature comprises two categories of names: 1. Names, or
rather terms, which express the nature of the groups comprehended one within the
other. 2. Names peculiar to each of the groups of plants that observation has
made known.
Art. 9. The rules and recommendations of botanical nomenclature apply to
all classes of the plant kingdom, recent and fossil, with exceptions which are
expressly specified.
Chapter II. On th e m a n n e r of d e s ig n a tin g th e n a tu re an d th e su b o rd in a tio n
of th e g ro u p s which c o n s titu te th e p la n t kingdom.
Art. 10. Every individual plant belongs to a species (species), every species
to a genus (genus), every genus to a family (familia), every family to an order (ordo),
every order to a class (classis), every class to a division (divisio).
Art. 11. In many species we distinguish varieties (varietas) and forms (forma),
in the case of parasites special forms (forma specialis)', and in some cultivated
species, modifications still more numerous; in many genera sections (sectio), in many
families tribes (trihus).
Art. 12. Finally if circumstances require us to distinguish a greater number
of intermediate groups, it is easy, by putting the syllable sub before the name of a
group, to form subdivisions of that group. In this way subfamily (subfamilia) designates
a group between a family and a tribe, subtribe (subtribus) a group between
a tribe and a genus, etc. The arrangement of subordinate groups may thus be
carried, for wild plants only, to twenty-two degrees, in the following order: Regnum
vegetabile. Divisio. Subdivisio. Classis. Subclassis. Ordo. Subordo. Familia. Subfamilia.
Tribus. Subtribus. Genus. Subgenus. Sectio. Subsectio. Species. Subspecies.
Varietas. Subvarietas. Forma. Forma specialis. Individuum.
If this list of groups is insufficient it can be augmented by the intercalation
of supplementary groups, so long as these do not introduce confusion or error.
Example: Series and Subseries are groups whicli can be intercalated between subsection
and species.
Art. 13. The definition of each of these names of groups varies, up to a
certain point, according to individual opinion and the state of the science, but their
relative order, sanctioned by custom must not be altered. No classification is admissible
which contains such alterations.
Examples of inadmissible alterations are, — a form divided into varieties, a species containing
genera, a genus containing families or tribes.
Art. 14. The fertilization of one species by another gives rise to a hybrid
(hybrida)', that of a modification or subdivision of a species by another modification
of the same species gives rise to a half-breed (mistus, mule of florists).
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