Flag for Taxon: Crape Myrtle Mildew (Erysiphe lagerstroemiae)
| Flagger | Content Author | Content | Reason | Flag Created | Resolved by | Resolution |
|---|---|---|---|---|---|---|
| sbrobeson | Crape Myrtle Mildew (Erysiphe lagerstroemiae) |
it is unclear what the standing of this taxon is |
Mar. 25, 2024 04:25:27 +0000 | sbrobeson |
swapped |
Comments
But Erysiphe australiana has the basionym Uncinula australiana 1899
https://www.indexfungorum.org/Names/NamesRecord.asp?RecordID=464030
That is the vastly older name than Erysiphe lagerstroemiae 1933.
Back in 1977 our Keith Hammet in New Zealand Journal of Botany, 1977, Vol. 15: 687-711 wrote "West (1933) described cleistothecia from L. indica in Florida as a new species, Erysiphe lagerstroemiae West, but on the collections made in New Zealand there is no evidence that more than one mildew species is involved"
More recently there was a poster at the 2005 MSA meeting by "Shi, Ainong and Mmbaga, Margaret T. Tennessee State University" which in the abstract says "This study provides conclusive evidence that that E. lagerstroemiae and U. australiana are the same. Because of international nomenclature rules, the name E. lagerstroemiae take priority over U. australiana. Thus, E. lagerstroemiae (syn. U. australiana) reported in the USA is the causal agent of powdery mildew pathogen in crape myrtle in mid-Tennessee and in China, Japan and Australia".
So the consensus seems to be that the two names are synonyms. I'm puzzled why these authors and you believe E. lagerstroemiae has priority. Am I missing something?
For my part, I just mixed up the chronological order -- sorry! I agree with your take nomenclaturally; E. australiana should take priority based on U. australiana. I can't speak for why those other authors thought that E. lagerstroemiae would have priority, but I don't know if I'm missing something further myself.
Nevertheless, again, in either order the two should be synonyms. Drafted a swap here (based on the inferred synonymy of E. lagerstroemiae under E. australiana): https://www.inaturalist.org/taxon_changes/141511
If something is found showing why E. lagerstroemiae instead should be the accepted name, the swap can be directly edited to reverse its direction.
The 1987 version of Braun's monograph states:
E. lagerstroemiae West (1933, p. 817). No powdery mildew. The author described two types of mycelium, the hyaline mycelium belongs to Uncinuliella australiana, the persistent, brown, thick-walled mycelium does not belong to the Erysiphales, rather to the Meliolinae. I could not locate the type material of this fungus, but I studied some samples (ex herb. BPI) revised by West. All collections only showed the anamorph of U. australiana.
So, it seems Braun dismissed E. lagerstroemiae as a nomen ambiguum and not even worthy of synonymy.
In that case I think it's safe to conclude that all the "E. lagerstromiae" being identified on iNaturalist is good E. australiana. Interesting that the original description was another instance of confusion. Since taxon changes are not really taxonomic synonymy it'll probably be fine to commit, though I'll wait a bit for any other input. But on that note, do you think that it would be best to list E. lagerstroemiae as a "synonym" of E. australiana on here anyway?
yes I do.
The iNat use of 'synonyms' often includes misapplications and nomina ambigua. They usefully re-direct people to the right name(s). What is missing is the ability to flag the status of these 'synonyms' so people can trace why these non-synonyms are listed.
Nice catch, happy with that swap as drafted.
made the change, names automatically transferred, should be done processing the merge soon (despite the awful process of automatically reapplying the name identification by identification across every observation...)
I can't find anything significant in the literature regarding this name. It is absent from Braun & Cook's Taxonomic Manual of the Erysiphales, and doesn't make an appearance in the recent Bradshaw et al. series of phylogenetic studies. Everything I can find states that the common species on Lagerstroemia is Erysiphe australiana. (E. lagerstroemiae E.West is vastly older, about 67 years, than E. australiana U.Braun & S.Takam. Surely Braun didn't miss the earlier name outright?)
I'm starting to get concerned that this is another case where a straightforward common name has drawn in a large number of identifications based on a main host association that may not have anything to do with exclusivity or the real state of taxonomy. The current iNaturalist observations of E. lagerstroemiae are restricted to North America, while E. australiana is identified across the world, but I don't know if there is an actual distinction... other than English site language users, so many of them in America, being shown the name "Crape Myrtle Powdery Mildew".
@andydonegan @cooperj @nschwab