What am I?

1. I am a threatened plant.
2. My Maori name is "pua o te reinga" meaning flower of the underworld.
3. Thousands of me have been dug up over the years so people can use my root as an ornament.
4. I am pollinated by the short tailed bat and some of us are now housed in cages to protect us from possums.
5. I grow as a root like stem attached to the root of a host tree. My host root moulds into the shape of a fluted rose which is the very reason why people collect me.

Find out the answer next week...