Pilea microphylla also commonly known as rockweed, artillery plant, gunpowder plant is actually considered as a weeds and rarely cultivated.
They are easily found along drainside or mossy areas.
This particular one had started growing by itself on a kokedama ball, some of the seeds would had airborne or would have occurred from some other source and started to grow here. At first, I often pull off and throw them away as weed and as usual it still comes back time after time.
Then, I just thought it does look good when it was small and sort off create a tiny arrays of miniature plants and I had let it grow for these moment. Later did I realized that these are actually pilea species.
Surprisingly for this humble plant is being used as traditionally as folk medicine to treat several ailments. I doubt to recommend their uses as there are some contentions and require more research and study on these matters.
I would find it hard to believe if anyone is seeking to cultivate this one but if you do - these are some pointers:
Light
This is a shade loving, high humidity plant - do grow it in bright shade area - too hot & it will burn, too wet and it may rot away though it may able to tolerate and withstand wet feet.
Medium
I would recommend to grow this on sandy medium mix with moss. They can also grow on moss surface by the drain-side or on a clay bricks.
Water:
This may require on humid side and therefore requires constant watering - too dry and hot may cause this one to dry off and wither away.
Propagate:
This is a self-propagating plant - so therefore do feel free to uproot them off if they started to sprout out elsewhere as it is invasive - one of the reason this is considered as a weed because of this reason.
Anyway, do share with me your thoughts on this particular plant - I hope you find this particular one interesting.