cactus flower question

updated wed 27 sep 06

june m. dean on wed 27 sep 06

Hi All,

Years ago I bought a small cactus plant -
I think it was called mamarilla? - Don't
remember now. It's round and I put it in
a little ceramic pot - southwestern design -
and have it on my windowsill at work.

Yesterday I looked and there was a yellow
flower on top! I was surprised. I saw that
it was yellowish on top but didn't expect
that a flower was pushing up.

Anyway, today the flower is closed.
Is this a one day flowering? What kind of
cactus have I?

It's still a round bulb-type on top, but seems
to be growing less round as it gains a bit of
height.

June