Source: https://www.iapt-taxon.org/nomen/pages/main/art_61.html
Timestamp: 2019-04-23 02:56:57+00:00

Document:
61.1. Only one orthographical variant of any one name is treated as validly published: the form that appears in the original publication (but see Art. 6.10), except as provided in Art. 60 and F.9 (typographical or orthographical errors and standardizations), Art. 14.8 and 14.11 (spelling of conserved names), Art. F.3.2 (spelling of sanctioned names), and Art. 18.4, 19.7, and 32.2 (improper Latin terminations).
61.2. For the purpose of this Code, orthographical variants are the various spelling, compounding, and inflectional forms of a name or its final epithet (including typographical errors) when only one nomenclatural type is involved.
Ex. 1. Nelumbo Adans. (Fam. Pl. 2: 76. 1763) and ‘Nelumbium’ (Jussieu, Gen. Pl.: 68. 1789) are spelling forms of a generic name based on Nymphaea nelumbo L., and are treated as orthographical variants. Similarly ‘Musenium’ (Nuttall in Torrey & Gray, Fl. N. Amer. 1: 642. 1840), for which Pfeiffer (Nomencl. Bot. 2: 377. 1873) designated Seseli divaricatum Pursh as type, is an orthographical variant of Musineon Raf. (in J. Phys. Chim. Hist. Nat. Arts 91: 71. 1820), of which S. divaricatum is the original type.
Ex. 2. The epithet of Selaginella apus Spring (in Martius, Fl. Bras. 1(2): 119. 1840) is a noun in apposition, so that apus cannot be treated as an orthographical variant of the adjective apodus, used in Lycopodium apodum L. (Sp. Pl.: 1105. 1753). Spring cited L. apodum as a synonym of S. apus, but instead he should have adopted the former epithet and published “S. apoda”; consequently S. apus was nomenclaturally superfluous when published and is illegitimate under Art. 52.1.
61.3. If orthographical variants of a name of a new taxon or replacement name appear in the original publication, the one that conforms to the rules and best suits the recommendations of Art. 60 is to be retained. If the variants conform and suit equally well, the first author who, in an effectively published text (Art. 29–31), explicitly adopts one of the variants and rejects the other(s) must be followed (see also Rec. F.5A.2).
61.4. The orthographical variants of a name are to be corrected to the validly published form of that name. Whenever such a variant appears in a publication, it is to be treated as if it appeared in its corrected form.
Note 1. In full citations it is desirable that the original form of a corrected orthographical variant of a name be added (Rec. 50F).
Ex. 3. ‘Geaster’ (Fries, Syst. Mycol. 3: 8. 1829) and Geastrum Pers. (in Neues Mag. Bot. 1: 85. 1794) : Pers. (Syn. Meth. Fung.: 131. 1801) are similar names with the same type (see Taxon 33: 498. 1984); they are treated as orthographical variants despite the fact that they are derived from two different nouns, aster (asteris) and astrum (astri).

References: Art. 6
 Art. 60
 Art. 14
 Art. 18
 Art. 52
 Art. 60