Isonym
An isonym, in botanical taxonomy, is a name of a taxon that is identical to another designation, and based on the same type, but published at a different time by possibly different authors. Citation from that source follows:
That is, the later isonyms are to be discarded, and only the first one is to be used.
An exception is made for family names that have been conserved; the place of publication listed for those names is considered to be correct and the name valid, even if an earlier publication of the same name is discovered.