Starburst agave -- NOT!
On the thread about the SAS Nursery in Austin a photo of an unknown plant purchased there was posted. Rick in Oklahoma, who got me started with Pink pentapetes, ID'd it for us. It's a cactus! Who'd a thunk it? It's thornless however and not very common even in its native habitat of Northern Mexico.
There is just no end to interesting plants in the world!
Here is a link that might be useful: Leuchtenbergia principis ....