Maurice Kellet advises it's from seed from Alfred Lau in the late 70's but not named with great confidence.
Derek Butcher reminded us of name change and notes...
"I had thought that petal colour would help in identification (green or violet blue) but there is too much confusion here. Harry says that in his opinion where the branches are vertical (flat side at right angles to the axis) you have T. cretacea, or horizontal (flat side to the axis) you have T. mooreana. Armed with this information you see that the plant in Peter's photo covers both, which means the plant does not know if it is Arthur or Martha !
I would suggest this be called T. aff. mooreana ( inflata ex Lau.). If we put photos on the Aust. website, others can look up the reference in years to come when they flower that T. inflata from Maurice."
Refer to "Detective Derek" article DD0809 for more details.