[snip] One of the rhizomes had some mold on it and hopefully did not transfer
to the others. [end snip]

If you there is even a small chunk of the "rotted rhizome" that is still firm to
the touch, you can try and cut off the rot and plant the firm part. However,
once a rhizome starts to go, usually it's toast.

I hope you get your last 36 to sprout. That'd be AMAZING. Good luck, and keep
us posted! John