A decade ago or so, there was not so much of this plant around but Brian and I collected some seed with thanks due to Arturo Anaya. It was growing on cliffs near toluca slightly north of Mexico City. C and J had some seed and Huntington as well as Rancho Soledad and it is now grown at RTT as well.
Same with cante which we collected in Zacatecas.
This latest plant is one that Brian, Julia Etter and I found growing with Echeveria patriotica (nayaritensis?) in Jalisco. It looks like a form of subrigida how it differs is it has crinkled leaves that are longer and skinnier as well and it is much less "frosted" the flowers are similar but again without plume or dusting on the flowers and stalks. That said it is not as different to me as it is similar. Some seedlings of the other form of subrigida came up with very crinkled leaves and so the variation to me is just that.
If you look up subrigida you should see reference to E. palmeri which is essentially a green form of subrigida but of a more typical shape that is flat rounded leaves not acuminate like this one.
So what is it?
a different form of E. subrigida or a new species or an intergrade between subrigida and nayaritensis.
Jury is out!
Ask Brian!
Kelly G