Hmmm...Could it be a calathea of some form? Or--a Philodendron?
Your small, black gnats are Fungus Gnats. They live and propagate (as larvas) in moist/wet soils.
First step is to keep your soil on the dry side. 2--put sharp sand or powdered up egg shells on top pf the soil. Best would be "Diatomaceous Earth" which is powdered silica.
See what the article can do to help you--or--Google "eliminating Fungus Gnats from houseplants.
http://www.metacrawler.com/met...
Gita
