why they were separated out into their own genus (Neobesseya).
Deciduous flower remains? Strongly embedded growth habit?
Or the genetic differences that Crozier reported, albeit with selected samples that almost guaranteed segregation? It might be interesting to consider the close relationship shown between C. macromeris and Neobesseya (E. missouriensis and E. robinsorum in this sample) while C. sulcata and E. tuberculosa are separated with some Mammillarias and Pelecyphoras respectively. From these five sampled species, the genus Coryphantha appears to be a completely unnatural grouping.