The unique and interesting hybrids of Pachyphytum, Echeveria and others create a group of intergeneric (two genera) hybrids that show traits and characteristics of both parents.
Pachyphytum have traits like loosely attached leaves with a shrubby type growth habit. Echeveria often have rosette type growth, with varying leaf forms, sometimes chubby, often more refined.
The combination of these genes often results in some unique forms, some of them not recognizable as one or the other.
That's when you know you've got a hybrid between them.
Some of these hybrids are extremely shy to flower.
Others seem to be quite prolific at producing blooms, which show intermediary forms between the parents.
This is one thing that makes them immediately recognizable; the shape and arrangement of the flowers.
The similarities between all these generic hybrids makes it really difficult to hone in on exactly which parentage your plant has.
Fortunately, they all require similar care - bright light, well drained soil, and the occasional hair cut and fertilizing.