This is a bit tricky .... could not find the term in some of my major taxonomy references ... this was what I found online ... the only reference that you do not need to be a plant lawyer to read ....

"5. Autonym - an automatically created name for infrageneric or infraspecific taxa, e.g. Arnica subgenus Arnica or Arnica cordifolia Hook. subspecies cordifolia. Not genuina or typicus. "

Sounds like your statement above but it is different ... I think your message above is a bit jargled ...This is tuff I'd rather give birth ( and I'm a man ) ... the automatic part is refering to the second "cordifolia" term in example # 5 above. Your example is NOT a autonym if it were it would be like Rosa carolina var. carolina.No other names needed... believe me.

WHY ?
This implies that Arnica cordifolia Hook. subspecies cordifolia ( a sub rank of Arnica cordifolia Hook. ) is very close to the taxa but different then Arnica cordifolia Hook. and more different then for example Arnica cordifolia Hook. subspecies mollis Hook..

I hope that makes sense it sounds worse then it is ....

Good Day ...... great post !

Gillmass ,

Another point of view ... it is done this way because the rules of botanical nomenclature say it must be done this way ... one could use the name ... Arnica cordifolia Hook. subspecies ( whatever neme you want if you were the taxonamist ) and imply it is a sub taxa or a better term a infraspecific taxa of Arnica cordifolia Hook. BUT the rules say you must automatically use the second part of the species name and arrive at Arnica cordifolia Hook. subspecies cordifolia . Perhaps in keeps things more orderly ....

Good Day ....

I don't understand the above explainations. Perhaps I am just saying the same thing. Here goes:

When you identify a group of plants as being a subspecies then it implies that they are different from the normal form of the species. So, the normal form is therefore identified as a subspecies with the same name as the species--the autonym. Now what I am not sure is if the "normal" is actually the type for the species or the form found to be the most prevalent.

I don't know ...

I think I'm going to have to get a copy of the nomenclature rules ... I'm afraid.... glad you came along.

The plant first collected would be the type I would guess ... anything different but not considered another species would be a subspecies. OK simple enough ... but what do we call all of these ??

In my flora there is a :

Chorizanthe brevicornu Torr. ssp. brevicornu
and a ssp. spathulata (Small) Munz

Now does this mean there are only two taxa out there or is there a Chorizanthe brevicornu Torr. out there as well ??

Or I suppose there are ways of determining who is a subspecies of who ?? After the fact ?? I don't know.

Thanks Jon ....