DIVISION II. RULES AND RECOMMENDATIONS
CHAPTER III. NOMENCLATURE OF TAXA ACCORDING TO THEIR RANK
SECTION 2. NAMES OF FAMILIES AND SUBFAMILIES, TRIBES AND SUBTRIBES
18.1. The name of a family is a plural adjective used as a
noun; it is formed from the genitive singular of a name of
an included genus by replacing the genitive singular inflection (Latin
-ae, -i, -us, -is; transliterated Greek -ou, -os, -es, -as, or -ous, and its equivalent
-eos) with the termination -aceae (but see Art.18.5).
For generic names of non-classical origin, when analogy with classical
names is insufficient to determine the genitive singular,
-aceae is added to the full word. Likewise, when formation from the genitive singular of a generic name
results in a homonym, -aceae may be added to the nominative singular. For generic names with
alternative genitives the one implicitly used by the original author
must be maintained, except that the genitive of names ending in -opsis is, in accordance with botanical tradition, always -opsidis.
Family names based on a generic name of classical origin: Rosaceae
(from Salix, Salicis
(from Rhodophyllus, Rhodophylli
(from Rhodophyllis, Rhodophyllidos
(from Aextoxicon, Aextoxicou
(from Potamogeton, Potamogetonos
Family names based on a generic name of non-classical origin: Nelumbonaceae
declined by analogy with umbo, umbonis
18.2. Names intended as names of families, but published with
their rank denoted by one of the terms "order" (ordo) or "natural
order" (ordo naturalis) instead of "family", are treated as having been
published as names of families (see also Art. 19.2),
unless this treatment would result in a taxonomic sequence with a misplaced rank-denoting term.
Ex. 3. Cyperaceae
Juss. (1789), Lobeliaceae
Juss. (1813), and
Fr. (1820) were published as "ordo Cyperoideae
", "ordo naturalis
", and "ordo Xylomaceae
If the term "family" is simultaneously used to denote a rank different from
"order" or "natural order", a name published for a taxon at the latter rank cannot be considered
to have been published as the name of a family.
Names published at the rank of order
("řad") by Berchtold & Presl (O přirozenosti
.... 1820) are not to be treated as having been published at the rank of family, since the
term family ("čeleď") was sometimes used to denote a rank below the rank of order.
18.3. A name of a family based on an illegitimate generic name is illegitimate unless conserved.
Ex. 5. Caryophyllaceae
Juss., nom. cons. (from Caryophyllus
Mill. non L.);
R. Br. ex Lindl., nom. cons. (from Wintera
Murray, an illegitimate synonym of
J. R. Forst. & G. Forst.).
18.4. When a name of a family has been published with an
improper Latin termination, the termination must be changed to conform
with the rule, without change of the author citation or date of
publication (see Art. 32.7). However, if such a name is published with a non-Latin termination, it is not validly published.
Ex. 6. "Coscinodisceae"
(Kützing 1844), published to designate a family, is to be accepted as
Kütz. 1844 and not attributed to De Toni, who first used the correct spelling (in Notarisia 5: 915. 1890).
Ex. 7. "Atherospermeae"
(Brown 1814), published to designate a family, is to be accepted as
R. Br. and not attributed to Airy Shaw (in
Willis, Dict. Fl. Pl., ed. 7: 104. 1966), who first used the correct
spelling, or to Lindley (Veg. Kingd.: 300. 1846), who used the spelling
However, Tricholomées (Roze in Bull. Soc. Bot. France
23: 49. 1876), published to designate a family, is not to be accepted
Roze", as it has a French rather than a Latin termination. The name
was finally validly published by Pouzar (1983; see App.
18.5. The following names, of long usage, are treated as validly published:
Compositae (Asteraceae; type, Aster L.); Cruciferae (Brassicaceae; type, Brassica L.); Gramineae (Poaceae; type,
Poa L.); Guttiferae (Clusiaceae; type, Clusia L.); Labiatae (Lamiaceae; type, Lamium L.);
Leguminosae (Fabaceae; type, Faba Mill. [= Vicia L.]);
Palmae (Arecaceae; type, Areca L.); Papilionaceae (Fabaceae; type, Faba Mill.); Umbelliferae (Apiaceae; type,
Apium L.). When the Papilionaceae are regarded as a family distinct from the remainder of the Leguminosae, the name
Papilionaceae is conserved against Leguminosae.
18.6. The use, as alternatives, of the family names indicated in parentheses in Art. 18.5 is
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