54.1. Consideration of homonymy does not extend to the names of taxa not treated as plants, except as stated below:
(a) Later homonyms of the names of taxa once treated as plants are illegiti-mate, even though the taxa have been reassigned to a different group of organisms to which this Code does not apply.
(b) A name originally published for a taxon other than a plant, even if validly published under Art. 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45 of this Code, is illegitimate if it becomes a homonym of a plant name when the taxon to which it applies is first treated as a plant (see also Art. 45.5).
Note 1. The International code of nomenclature of bacteria
provides that a bacterial name is illegitimate if it is a later
homonym of a name of a taxon of bacteria, fungi, algae, protozoa,