A 15watt bulb over a 10 gallon tank is only 1.5 wpg. Unless you want to upgrade your lighting by buying a new fixture or a retrofit kit, you need to be looking at low light plants. You can probably keep a lot of other plants alive under that amount of light, but they won't thrive.
For a long time, I only had 20watts on my 29 gallon, and I had a sword, dwarf sag, h. polysperma, rotala rotifunda and rotala macranda. They were all alive, but they weren't growing until I added better lighting.
If you want to stick with low light plants, you can look at java ferns and some of the crypts. I also just added lymnophila sessiflora to my low light 6 gallon, and so far it seems to be doing really well.
29g Eheim Classic 2213, community, heavily planted, 65W CF, 2x Hagen CO2
20g Fluval 3 Plus, nothin' but shrimp & snails, 65W CF, Hagen CO2