It's a type of ginger, a Costus, but not sure which species or variety/cultivar. They grow very easily from cuttings (and can even become a bit weedy).

Grows tall, didn't know gingers got that big, must be two meters high at least,,,Interesting flower, the bee has to push past a 'door' to enter to pollinate...

Christopher

There's quite a range of different gingers, some grow very tall. Etlingeras can get to about 5 metres tall. I've got some that height. My tallest Costus get to 2+ metres, but I also have some smaller ones. Alpinias are another that can get up 4 to 5 metres. Their flowers can be quite unusual.

Hi
I have some Alpinias generally called shell ginger here , ,which are pushing 20 feet tall lol With stalks 4 inches in diameter . I made a mistake planting them in a shrub border
had no idea ANY ginger got that big lol. Very attractive flowers and are evergreen but want to take every square inch of the border. lol Incredible range of flowers ,leaf forms and habits iin that wonderful family except for those that go dormant during winter lol
tropic The Cassia roxburghii has finished flowering and has NOT produced a single seed!!! Hooray Sure not like the rest of the family!! gary

That's the trouble with a lot of gingers, just like heliconias. They don't know any limits, and just keep going. But funnily enough, the Costus and some of the other gingers are chewed right down to the ground by wallabies late in the dry season. Seems when other feed becomes more scarce they don't mind the taste of ginger.