DIVISION II. RULES AND RECOMMENDATIONS
CHAPTER I. TAXA AND THEIR RANKS
The principal ranks of taxa
in descending sequence are: kingdom (regnum), division or phylum
(divisio, phylum), class (classis), order (ordo), family (familia),
genus (genus), and species (species). Thus, each species is assignable
to a genus, each genus to a family, etc.
Species and subdivisions of genera must be assigned
to genera, and infraspecific taxa must be assigned to species, because their names are
combinations (Art. 21.1
), but this provision does not preclude the placement of
taxa as incertae sedis with regard to ranks higher than genus.
The genus Haptanthus
Goldberg & C. Nelson
(in Syst. Bot. 14: 16. 1989) was originally described without being assigned to a family.
The family assignment of the fossil genus Paradinandra
Schönenberger & E. M. Friis (in Amer. J. Bot. 88: 467. 2001) was given as "incertae sedis".
The principal ranks of
nothotaxa (hybrid taxa) are nothogenus and nothospecies. These ranks
are the same as genus and species. The prefix "notho" indicates
the hybrid character (see
(c) 2006, by International Association for Plant Taxonomy. This page last updated