Astrophytum
Star-shaped bodies. Yellow flowers with red centres
!

Astrophytum myriostigma
!
astrophytum_myriostigma7
Larger picture 
"Bishop's Cap Cactus"
ex 7cm pots

Astrophytum ornatum
!
astrophytum_ornatum

Astrophytum ornatum f. glabrescens
!
astrophytum_ornatum_glabres
ex 9cm pot

Astrophytum ornatum mirbellii
!
ex 7cm pots