The flower of the Bowiea volubilis is strange - no petals, just sepals and reproductive parts. Curious I did a search of 'flower with no petals and came up with Tepal, (new word for me) The online Dictionary of Botany defines tepal as:
tepal
An individual perianth part in flowers that have no distinct calyx and corolla, as occurs in most monocotyledons. In the tulip the tepals are all highly coloured.
So I'm thinking it's a tepal.
Can someone confirm or give me the right word for what's going on with the Bowiea flower?