Summary of previous discussion by Gregor, Rich, and Sally (please refer back to version r1.10 of this page for the original contributions):
Rich's original definition about the equality of protonym and basionym was discussed and questioned.
We worked out that in the botanical sense "basionym" is a relationship term rather than a kind of name (a name can have a basionym but can't be a basionym), and does not apply to replacement names:
Richard: In my mind (not sure if this is true in the minds of other zoologists), Nomina novae/repl.names do not "have" a basionym. Rather, they are treated as objective (homotypic) synonyms. In zoology, I believe there is no authorship connection between the two names. Of course, in zoology we have no "Basionym", so there is no "name-level" connection between a Replacement name and the name that it replaces (other than the fact that, by definition, they are homotypic). -- 02 Nov 2004
Gregor: Checking the bot. code (ICBN), basionym is defined as "name-bringing or epithet-bringing synonym". The term basionym is avoided in the replacement name case ("nom. nov."). The term used in ICBN 33.3 for this is "replaced synonym". The authorship of the replaced name is not included in the case of replacement names in botany. From authorship formatting it is not visible that a botanical name is based on another name - it looks like an original name (nice that zoology and botany are similar here!).
Rephrasing of the above by Rich to clarify: "in botanical practice, a name that is replaced is not, strictly speaking, the "basionym" in a "Nom. Nov." relationship; instead is is called "replaced synonym" in botany. This means that a Nom. Nov. has no Basionym."
From email by Paul Kirk: "A basionym is a relationship term. A name is a name is a name, and although there has been a tendancy to label one type of name as a basionym (basal name) the word correctly defines the relationship between one name (the first in a series) and another name (a subsequent name - a New Combination). You are also correct that with this definition it makes no sense to say "This is a (the) basionym" without adding "basionym of ...". -- Paul
Gregor: Basionym and replaced synonym are closely related: "To my (presumably botanical) thinking, nom. novum is a variant of comb. nov., i.e. a recombination which does not change the type concept. It has the extra problem that the epithet has to be changed; instead of only changing the genus part, you change both Genus and epithet. For many analysis purposes, and in regard to intellectual contributions of by two author teams, comb. nov. and nom. nov. are the same.
A diagram attempting to clarify the terms: See diagram (is this correct?):
--------------- Protonym -------------------------- -------- --------- Derived name (?) --------------
- Original name -- -- Nom.nov./replacement name -- -- comb.nov./recombined name -- -- stat. nov. --
- (not based on -- ---- has replaced synonym ----- ------------------ has basionym ------------------
-- other name) --- ----------------- ## COMMON TERM FOR THIS? BasedOn? BasalName ## -------------------
Gregor: I would love to have a term for the place marked with "##". I tend to think about it as "basionym", but clearly this differs from the usage in the ICBN. Something like "BasedOn" could be a single element in LC, there is no competition for it among the different creation types (tax. nov., stat. nov., comb. nov., nom. nov., see LCNameCreationTypeDiscussion). However, I don't fully like BasedOn, since a concept may also be based on another concept. BasedOn is a bit too general, I think. Paul Kirk used "BasalName" which may be better? I propose to use this term in the LinneanCore! - 7 Nov 2004
Gregor: It seems James proposes Basonym (not Basionyme) on LinneanCoreDefinitions as a name for the basal name. To me that seems to call for confusion, because those two are pronounced in English essentially the same, and even in writing they look very close. I would rather stay with BasalName in English. Although having another xxxnym in the series may be very tempting.
JMS: Basonym is not my invention; it comes from ICNB. I picked it because I do not want to re-invent new jargon for already used one. Basionym is the earliest basonym; all basonyms are synonyms (perhaps). What we need is clearer terms and their translations to existing terms, just as the table provided by BioCode. - 08 Nov 2004
Gregor: Thanks, I did not know that. If established forget the comment above. Googling tells me that a the term is used in bacteriology but I did not find Basonym in the ICBN context on the internet - can someone provide a definition of it? I see now that Rich himself provides a definition in the taxonomer publication: "Basonym” (without the “i”) is defined in Merriam-Webster's Third New International Dictionary as: "The earliest validly published name of a taxon, being in the case of a binomial or trinomial the source of the valid specific or subspecific epithet when the taxon is transferred to a new combination and in technical usage always accompanied by the name of the original author. (Crataegus spicata Lamark:Amelanchier spicata]" -- this leaves in my eyes the question open whether synonymy as James mentions is homotypic only or also heterotypic synonymy. -- PS: the definition also appears on a puzzle-page (sic!) listing all words ending with "nym": http://rec-puzzles.org/new/sol.pl/language/english/spelling/nym. - 08 Nov 2004
See also LCNomenNovumDiscussion. Conclusion of that: The relation-types basionym and replaced synonym point to a protonym and are not more specific. A comb. as well as nom. nov. can be based on either of original name or replacement name, depending on the situation.