Meaning of an embedded sentence and how this usage is called (example)

I have stumbled upon on the following sentence, and I do not understand how the bold one is related to the others:

And here, in Saddoth, beyond the domes and terraces and columns of the
huge necropolis, a necromantic flower wherein forgotten lilies live
again, there bloomed the superb and sorrowful loveliness of
Thameera,

What does this sentence (in bold) relate to? If I take it out, the meaning of the whole construction seems to be the same. But I am unsure – is the flower referring to the necropolis, or to Thameera?