Thank you for the offer Rex, but I do have regular riccia. Hehehe. Yeah, I've only heard of this plant recently.

Apparently, it has been "out there" for a while but has never gained any notoriety, not unlike
Ammania sp. 'Bonsai' and
Eusteralis verticillata.
The mini riccia is, like its namesake, a miniature version of regular
Riccia fluitans. After doing some research, hobbyists describe it as "more refined", "mossy", and "slower growing" than regular riccia. Sounds exciting.
Here is a
pictorial comparison of the two forms. And here is a photo from the Plant Finder:
So does anyone have this nifty liverwort?