There are a few alternative names for Laurelin, and two of them begin with M. But am I right in assuming we need to look for another source of light, not another name for one we already have?
I know ... MEWLIPS' CANDLE! That's a light source!
'With single sickly candle lit
And there they count their gold.
Oh damn ... too late. The hobbit songs are Third and early Fourth Age.