[VierScar]

What do you mean by "on" rice? On the living plant? Or you mean it's growing in a jar of rice?

A bioluminescent wood nightlight sounds amazing, surely someone sells them

[dekhn]

https://www.instructables.com/Growing-Mushrooms-With-Rice/

[AyyEye]

Rice (flour) is a common substrate to grow mushrooms. Make sterilized/hydrated rice cake and inject some spores into it.

[ceejayoz]

I have four bioluminescent petunia houseplants above my bed for that.

[someothherguyy]

I was curious, and here is a video of the product (not trying to push marketing).

https://youtu.be/iaE7EsW-x_A?feature=shared&t=98