Schriften zu Genetischen Ressourcen - Genres

Theoretical and practical problems in the classification and nomenclature of cultivated plants
Fig. 1: The classification of Cucurbita pepo
Note that the cultivar-groups are subordinated to varietates. If these groups
were recognised as convarietates, then it would be necessary to raise the
varietal taxa to a rank (e.g., infraspecies) intermediate between subspecies
and convarietas, as the rank of varietas is subordinate to the rank of convarietas.
Denomination classes and homonymy
Under the Botanical Code, the use of the same epithet in heterotypic names of two or
more taxa of infrageneric, supraspecific rank, or of infraspecific rank, irrespective of
the actual ranks of the taxa concerned, is not permitted. Only the earliest of such
homonyms may be taken into consideration for purposes of priority in establishing
the correct name of a taxon; the others must be rejected as illegitimate. However, the
use of the same infraspecific epithet for names of taxa subordinate to species placed
under different species or genera is allowed. This provision is advantageous in the
naming of cultivated plants, as it permits the use of the same epithet in the names of
corresponding elements of two or more homologous series of infraspecific taxa of
two or more different species within the same genus, as well as for those in different
genera. On the other hand, under the Cultivated Code, the taxon within which the
use of a cultivar or cultivar-group epithet may not be duplicated is the denomination
class, which is a genus unless a special denomination class (which may be wider or
narrower than a genus) has been determined by the International Commission for the
Nomenclature of Cultivated Plants. In Compositae, for example, Cichorium and Lactuca
fall within one denomination class, as in Cucurbitaceae do all the species of Cu-
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Cucurbita pepo
ssp. pepo var. fraterna
var. pepo
Aurantia Group
Pumpkin Group
Styrian Hulless Group
Vegetable Marrow Group
Vegetable Spaghetti Group
Cocozelle Group
Zucchini Group
ssp. texana var. texana
var. ovifera
Ornamental Gourd Group
Scallop Group
Crookneck Group
Straightneck Group
Delicata Group
Acorn Group