Sacha is away now, but I mailed her last night with a 95% certainty of
it being Ruspolia hypocrateriformis. Having since 'discussed' this
with folks in the US I can now confirm it to be that species. At
first, I dismissed it as being hypocrateriformis because the few
plants I've seen were so markedly different to the original pic.
However, the second pic and viewing the plant 'in person' reassured me
it was Ruspolia after which, I had to review my thoughts about the
species. Anyway, the mystery is finally solved.