That's behind a paywall, unfortunately. However, the situation is: Willdenow published the name "Knoxia simplex" in 1818. Kunth published the name "Spermacoce diversifolia" in 1819, and cited Knoxia simplex as a synonym. Spermacoce diversifolia is therefore a superfluous name—a new name published for a taxon that already had a legitimate name. Consequently, Spermacoce diversifolia Kunth is illegitimate, and Crusea diversifolia (Kunth) W.R.Anderson is likewise illegitimate. In other words, this is a nomenclatural change, not a taxonomic change.
Sorry, guess I wasn't clear. I'm not proposing a deviation—I wanted to understand what the POWO taxonomy was based on and, since POWO does not provide that information, I thought it might be useful to any other curious parties for me to provide it here.
Los desacuerdos no deseados ocurren cuando un padre (B) es
disminuido al mover un hijo (E) a otra parte del árbol taxonómico,
resultando en que los IDs existentes del padre sean interpretados
como desacuerdos con los IDs existentes del hijo movido.
Identification
ID 2 del taxón E será un desacuerdo no deseado con la ID 1 del taxón B después del cambio de taxon
Si disminuir a un padre resulta en más de 10 desacuerdos no deseados, debes dividir al padre después de cambiar al hijo para reemplazar las identificaciones existentes de
el padre (B) con identificaciones que no están en desacuerdo.
The situation is described here: https://onlinelibrary.wiley.com/doi/abs/10.1002/tax.12183
That's behind a paywall, unfortunately. However, the situation is: Willdenow published the name "Knoxia simplex" in 1818. Kunth published the name "Spermacoce diversifolia" in 1819, and cited Knoxia simplex as a synonym. Spermacoce diversifolia is therefore a superfluous name—a new name published for a taxon that already had a legitimate name. Consequently, Spermacoce diversifolia Kunth is illegitimate, and Crusea diversifolia (Kunth) W.R.Anderson is likewise illegitimate. In other words, this is a nomenclatural change, not a taxonomic change.
https://www.tropicos.org/name/27905976
https://www.tropicos.org/name/100211544