I've used these and had good luck with them. They're some sort of aponogeton. Do you have a heater in your tank? They usually do best at tropical temps in the high 70s. Have you ever used any kind of algecide? Did you try to bury the bulb in the gravel? If you did, don't do that, or the bulb will rot rather then sprout. Just let them float or sink, and after they put out shoots and a bit of roots, bury only the roots in the gravel, leaving most of the bulb above the gravel.