Canna seeds are quite large, so I'd say yours were not pollinated and didn't develop.

Your seeds are definitely not viable and as stated above the fertilization process was incomplete. Most likely your cultivar is incapable of producing viable seed (sterile).

If you could include a photo of your plant blooming we might be able to identify the cultivar. Several of our large flower hybrids are sterile.

Kent

Mine are the same. Were you able to figure out why?

Mine are also bright orange and just tiny seeds for many years they flower nicely but no seeds.

As stated several years ago, there are several of our large flowered canna cultivars that are incapable of producing viable seed. The orange flowered cultivar above appears to be C. Wyoming. This particular cultivar will likely never produce viable seed because the plant has three times the haploid number of chromosomes (Triploid plant). Canna cultivars that produce viable seed are the "Diploid" plants having only twice the number of chromosomes normally occurring in a mature germ cell. Most plant somatic cells are diploid.

Kent

Thank you for your reply. Not sure why you needed to reiterate that you already stated this years ago ... it seems as if you found fault with my question because this was answered already. My apologies, I didn't mean to bother you.

rubyt: My reply was not specifically direct at your cultivars growing results; typically found in C. Wyoming. It was quite accurate. The reply is intended to point out that "sterile" plants do not produce viable seed. That term "sterile" was stated by the original poster and my confirmation years ago. Apparently I thought it necessary to expound on this thread after a photo was posted and any future reader will find this of value. Question above: "Were you able to figure out why?"

Kent

this is my second year growing cannas, and i always wondered why i am finding all these purple and black marbles on the ground,, i feel stupid after learning these are seeds,we all learn in different ways, and there is so much misinformation out there now a days,