I don't know how else to describe these flecks underneath the leaves, they look like tiny flakes of rust. They are all different sizes/shapes & decidedly not bugs of any sort (my mom has me worried about spider mites).

This plant is growing indoors & new to me - a big pot containing 6 tubers was given to me in October or so, which I split up (every one promptly lost all foliage!) into individual pots to give away. They all are doing fine now, but the largest one, which I kept, has these very distinct specks on the underside of the leaves, mostly at the veins & at the edge. There seem to be more of the flakes when the leaf in new & unfurling...

I don't think there's anything wrong with the plant; I'm just curious & guessing the flecks are some sort of mineral or a form of the oxalate crystals? That certainly would be a major disincentive to eat their big, juicy-looking leaves... if you were a browsing animal, that is...

Thanks for any info!