1. Tank size
2. Watts and type of lighting
10W, fluorescent aquarium lamp on for 6-7 hours.
3. Number and types of plants
Salesman did not tell me the type, but it looks a lot like Moneywort (see pics at bottom)
4. Substrate type
5. Age of tank
One year, but was cleared out and re-cycled in November 2011.
6. CO2 injection
8. Detailed description of plant problems
It'll become very clear why I need help. Yesterday I purchased this plant (at Byron's recommendation) and tried to plant it, but it has no roots. The salesman told me that it would root in gravel. But I'm having such a hard time getting it to stay in there that I'm worried it won't root. Some float, and some have managed to stay in the gravel. If they're floating will they just die? Also: will the others be able to develop roots at all? It seems like they're cut too high to be able to develop any. Pictures below.
Floating, rootless plant:
Here's my "planting" of the plant, with one sticking up out of the gravel:
A bunch of floating plants: