The explanation for this seems pretty clear, Zuzu.
ITIS has only dealt with the following former
Pulsatilla species, and has reassigned them to the genus
Anemone:
From the ITIS search on "Pulsatilla":
Anemone pulsatilla L. – accepted – European pasqueflower
Pulsatilla Mill. – not accepted – pasqueflower
Pulsatilla hirsutissima (Pursh) Britton – not accepted
Pulsatilla ludoviciana A. Heller – not accepted
Pulsatilla nuttalliana (DC.) Spreng. – not accepted
Pulsatilla occidentalis (S. Watson) Freyn – not accepted – white pasqueflower
Pulsatilla patens (L.) Mill. – not accepted – American pasqueflower, eastern pasqueflower, pasqueflower
Pulsatilla patens ssp. hirsutissima (Pursh) Zämelis – not accepted
Pulsatilla patens ssp. multifida (Pritz.) Zämelis – not accepted – American pasqueflower, cutleaf anemone, sticky pasqueflower
Pulsatilla patens ssp. patens (L.) Mill. – not accepted – American pasqueflower, eastern pasqueflower
Pulsatilla vulgaris Mill. – not accepted – European pasqueflower
"Every species name has been recategorized as a species of Anemone." Yes, since ITIS has only dealt with the species above, which have been reclassified to
Anemone), typing "Pulsatilla" into the search function gives the result "not accepted" for the word Pulsatilla. Do you see what I'm saying?
If you type other species of
Pulsatilla into the search function (e.g. other European and Asiatic species -
P. ajanensis, P. verna, P. aurea, P. turczaninovii, P. campanella, etc.), it ITIS does not say "not accepted". It says "No data found".
According to David Nicolson (Data Development Coordinator, Integrated Taxonomic Information System Biologist, USGS Core Science Systems, Core Science Analytics & Synthesis Program) this means ITIS has not dealt with the species. (If you look at the list for
Anemone in ITIS, you'll see that the species accounted for there are native or introduced N. American species or ones that are circumpolar. If you do a search on an Asian one, e.g.
Anemone rivularis, it also returns "No data found".)
It would seem presumptuous to assume that ITIS, without having studied the species, will conclude that they should be shoe-horned into the only species it has examined,
Anemone patens and
Anemone pulsatilla... or alternatively, if they can't be shoved into those species, that they would then be invalid species. Until these taxonomic sources actually "decide" on particular species (or until ITIS does, I guess, as that seems to be the main reference here), it's premature to second guess the validity (or invalidity) of a species name.
Anyway, I give up.
