Splitting Echinocactus

[KarlR]

Just came across this article by Vargas-Luna et al.
https://doi.org/10.3897/phytokeys.111.26856

They propose to split Echinocactus in two. A much smaller Echinocactus containing only E. platyacanthus and E. horizonthalonius (+ subsp. nicholii), and an expanded Homalocephala to house the remaining ones: H. polycephala (+ subsp. xeranthemoides), parryi, and texensis.

They also consistently find E. grusonii outside of Echinocactus, nestled in a Ferocactus clade. They use Lodé's combination of Kroenleina grusonii although they caution that it may be premature to use this name until its relationship with Echinocactus and Ferocactus is resolved.

It isn't a wholly new notion, but the genetic and morphological work they've done seems very solid.

They also suggest (pending more work) that it may be likely that there is grounds for recognising an Echinocactus-Ferocactus clade with the likes of E. grusonii/K. grusonii, F. glaucescens, histrix etc.

I am not averse to the change, and the work they've done seems very solid, but it feels a bit strange to have an Echinocactus genus with only platyacanthus and horizonthalonius. It doesn't feel quite natural to me and I'm sure there will be some more changes.

[Stuart]

Botanists seem to be able to play about with DNA results to prove almost anything, just ignore the results that don't fit in with the desired theory. I've always thought Ferocactus, Echinocactus and Leuchtenbergia could be one genus even though the name Leuchtenbergia would take precedence as the oldest name. At the same time Stenocactus Coptogonus seems a bridging link between Stenocactus and Ferocactus and maybe throw in Thelocactus for good measure. All those genera can be hybridised so they can't be far apart.

Stuart

[iann]

I must have missed this first time around. Just found it now in a search since I thought someone would have mentioned this. So now I have all the Homalocephala species, but only one of the (two) remaining Echinocactus. Of course, almost all the North American species were once called Echinocactus (or Echinocereus), hardly any left now.

[Aiko]

In the (latest) BCCS journal the name Glandulicactus was also dropped in relation to the same Echinocactus / Kroenleinia / Homalocephala naming suggestions. Which I personally find much weirder.

[KarlR]

In the (latest) BCCS journal the name Glandulicactus was also dropped in relation to the same Echinocactus / Kroenleinia / Homalocephala naming suggestions. Which I personally find much weirder.

What do you mean by dropped?

[iann]

In the (latest) BCCS journal the name Glandulicactus was also dropped in relation to the same Echinocactus / Kroenleinia / Homalocephala naming suggestions. Which I personally find much weirder.

That's not what I see from that paper. Glandulicactus was unresolved within the Ferocactus/Stenocactus/Thelocactus clade.

Echinocactus. Homalocephala, and Astrophytum form a separate clade. The decision to make/keep that as three separate genera is partly fashion (for not too much lumping), partly the strong differences in the appearance of the plants themselves (eg. Astrophytum have very obvious similarities to eachother and differences from the others). The relationships remain the same and a subtribe is suggested as a way to recognise their closeness.

[rodsmith]

As I've posted before, misquoting Shakespeare, A rose by any other name would smell as sweet.

[el48tel]

As I've posted before, misquoting Shakespeare, A rose by any other name would smell as sweet.

A-b-s-o-l-u-t-e-l-y-!