What does the phrase “the rose that grew from concrete” mean figuratively as used in this poem?

Poem:
Did you hear about the rose that grew
from a crack in the concrete?
Proving nature’s laws wrong it
learned to walk without having feet.
Funny it seems, but by keeping its dreams,
it learned to breathe fresh air.
Long live the rose that grew from concrete
when no one else ever cared.

Thank you! 100pts! Hope it helps, and really hope you can answer it!