DIVISION II. RULES AND RECOMMENDATIONS

CHAPTER I. TAXA AND THEIR RANKS

Article 1

1.1. Taxonomic groups of any rank will, in this Code, be referred to as taxa (singular: taxon).

1.2. Fossil taxa (diatoms excepted) may be treated as morphotaxa. A morphotaxon is defined as a fossil taxon which, for nomenclatural purposes, comprises only the one part, life-history stage, or preservational state represented by the corresponding nomenclatural type.

Note 1. Any fossil taxon that is described as including more than one part, life-history stage, or preservational state is not a morphotaxon.

Ex. 1. Alcicornopteris hallei J. Walton (in Ann. Bot, n.s., 13: 450. 1949) was described from fossil material that included a compression on the surface of a petrified nodule with anatomy permitting description of the rachides, sporangia, and spores of a pteridosperm. This species comprises two preservational stages, two life-history stages, and three parts of the plant and is therefore not a morphotaxon.

Ex. 2. Protofagacea allonensis Herend. & al. (in Int. J. Pl. Sci. 56: 94. 1995) was described on the basis of dichasia of staminate flowers, with anthers containing pollen grains, fruits, and cupules. This species comprises more than one part and more than one life-history stage and is therefore not a morphotaxon.

1.3. As in the case of form-taxa for asexual forms (anamorphs) of certain pleomorphic fungi (Art. 59), the provisions of this Code authorize the publication and use of names of morphotaxa (Art. 11.7).