Alright guys I've posted about this plant before, but I think I've narrowed it down:
1. It grows in COLD clear water (55-65°F)
2. It grows in nutrient poor substrate, bear rock, cling to other plants (such as on tree roots) or live free-floating
3. It's leaves are paired in twos
4. It stays relatively small, with leaves rarely getting more than an inch in diameter
5. in the right conditions, it will carpet its substrate.
6. (this last point is speculation btw) reproduces asexually through side shoots)
I'm starting to think it might be related to Lobelia cardinalis. It exhibits many of the same characteristics but grows in much colder water. Here's a picture of that plant for reference: (not mine) www.plantedtank.net/forums/ima…