"Yeah," breathed Harry, looking up at the end of the closest row. Beneath the branch of blue-glowing candles protruding from it glimmered the silver figure fifty-three.
Harry Potter and the Order of the Phoenix
I don't quite understand that sentence in bold above. I think the main verb is 'glimmered', but I failed to identify the subject of it.
I'm not sure what 'it' in "protruding from it" refers to.
And what does 'branch' mean in this context?