By Glowing
United Kingdom 
I have taken your advise and washed in water the Canna Lily and it does look so much better, although it is still rather large. One of the people who came back with help suggested it might be bulbs but this to me looks like a corm (not sure about spelling) does this look healthy to you?
6 Jan, 2018
Answers
It looks healthy to me, just store in a cool, dark & dry place with good airflow (the basement). I would give it a larger pot next year.
7 Jan, 2018
Previous question
yes my canna looks like this too. as long as the rhizome feels firm it will be ok. You can either re-pot it in fresh barely damp compost or in dry sawdust till the spring then pot up into compost. Mine is in dry sawdust along with the dahlia tubers.
6 Jan, 2018