The function of a violet is to grow out of dead leaves, turning decay into itself. A poem too builds a little sense from the rubble of life (what branches grow out of this stony *******?). One and the other flower according to their nature, seen by those who know what they are looking for.
A violet is not a poem, but the message is the same.
The quotation in brackets is from TS Eliot's "The Waste Land".