It is probably a seed head. It may, or may not be ripe enough to be viable. I would put it in a brown paper bag and leave it until the head dries enough to release the seeds. You can then plant them and see if they grow. Al

thanks for the response!

I googled gladiolus-like and found a page with Cannas that had similar spikey thing.

Here's another page with cannas and it shows the thing I picked off, but the seeds inside when ripe are huge in the picture, and mine are like grains of sand, so I'll throw them out.

Here is a link that might be useful: Canna seed head

Almost all bulbs produce seeds if not dead headed. Some will grow true to the parent,(clivia,agapanthus,dietes,galtonia)but you will have to wait up to five years for the first bloom, so most gardeners will propagate from divisions instead. Al