Have had real problems trying to identify this plant. A friend cultivated them in the UK a few years ago from bulbs they brought back from Hawaii.

They are basically like huge onions about 5-6ft in height which produce a single flower about this time of year which is comprised of about 20 separate stamens.

I have attached a photo of the whole plant in a separate post.

Having tried other gardening forums I've drawn a total blank so would really appreciate a proper i.d. - some guidance on care would also be much appreciated! Thanks.