Article H.10

H.10.1. Names of nothotaxa at the rank of species or below must conform with the provisions (a) in the body of the Code applicable to the same ranks (see Art. 40.1) and (b) in Art. H.3. Infringements of Art. H.3.1. are treated as errors to be corrected (see also Art. 11.9).

Ex. 1. The nothospecies name Melampsora ×columbiana G. Newc. (in Mycol. Res. 104: 271. 2000) was validly published, with a Latin description and designation of a holotype, for the hybrid between M. medusae Thüm. and M. occidentalis H. S. Jacks.

H.10.2. Taxa previously published as species or infraspecific taxa which are later considered to be nothotaxa may be indicated as such, without change of rank, in conformity with Art. 3 and 4 and by the application of Art. 50 (which also operates in the reverse direction).

H.10.3. The following are considered to be formulae and not true epithets: designations consisting of the epithets of the names of the parents combined in unaltered form by a hyphen, or with only the termination of one epithet changed, or consisting of the specific epithet of the name of one parent combined with the generic name of the other (with or without change of termination).

Ex. 2. The designation Potentillaatrosanguinea-pedata” published by Maund (in Bot. Gard. 5: No. 385, t. 97. 1833) is considered to be a formula meaning Potentilla atrosanguinea Lodd. ex D. Don × P. pedata Nestl.

Ex. 3. Verbascumnigro-lychnitis” (Schiede, Pl. Hybr.: 40. 1825) is considered to be a formula, Verbascum lychnitis L. × V. nigrum L.; the correct binary name for this hybrid is Verbascum ×schiedeanum W. D. J. Koch (1844).

Ex. 4. The following names include true epithets (but see Rec. H.10A): Acaena ×anserovina Orchard (1969) (from A. anserinifolia (J. R. Forst. & G. Forst.) Druce and A. ovina A. Cunn.); Micromeria ×benthamineolens Svent. (1969) (from M. benthamii Webb & Berthel. and M. pineolens Svent.).

Note 1. Since the name of a nothotaxon at the rank of species or below has a type, statements of parentage play a secondary part in determining the application of the name.

Ex. 5. Quercus ×deamii Trel. (in Mem. Natl. Acad. Sci. 20: 14. 1924) when described was considered as the cross Q. alba L. × Q. muehlenbergii Engelm. However, progeny grown from acorns from the tree from which the type originated led Bartlett to conclude that the parents were in fact Q. macrocarpa Michx. and Q. muehlenbergii. If this conclusion is accepted, the name Q. ×deamii applies to Q. macrocarpa × Q. muehlenbergii, and not to Q. alba × Q. muehlenbergii.

Recommendation H.10A

H.10A.1. In forming epithets for names of nothotaxa at the rank of species and below, authors should avoid combining parts of the epithets of the names of the parents.

Recommendation H.10B

H.10B.1. When contemplating the publication of new names for hybrids between named infraspecific taxa, authors should carefully consider whether they are really needed, bearing in mind that formulae, though more cumbersome, are more informative.