In The Scarlet Letter, what is the 'black flower'?

There are
two striking instances of the use of the phrase, 'black flower' in this novel. The first is in ,
when the narrator refers to the prison wherehas been incarcerated, as 'the black flower of
civilised society'. Later, in , whenand Hester meet each other alone by chance, and she pleads
with him to abandon his harrassment of , he refuses to do so, saying 'Let the black flower
blossom as it may'.

In both cases, the black flower's most obvious function
is as a symbol of retributive punishment - both that which is inflicted publicly by society and
privately by individuals. In either example, this symbol appears in a wholly negative light. The
prison is a blot upon society, and appears wholly bleak and depressing. Chillingworth, in his
hounding of Dimmesdale, often becomes the veryof vengeance  and it renders him a dark, bitter,
twisted figure, with virtually no redeeming qualities. 

It should be noted
however, that in his private meeting with Hester in Chapter 14, although he still appears
overwhelmingly grim, Chillingworth also expresses recognition that Hester is in herself not
necessarily evil, although her actions have been.

Ye that
have wronged me are not sinful, save in a kind of typical illusion; neither am I fiend-like, who
have snatched a fiend's office from his hands. It is our fate. 

Chillingworth, then, does not condemn Hester outright here, but he is unable to see
past her sin, the consequences of which, in his view, can never be eradicated.  In a fatalistic
way, he succumbs to wholly negative emotions. He cannot allow himself to deviate from the role
of vengeance that he has set himself, and this is hisas it makes him so bitter and unloving and
ultimately consumes him, as well as inflicting misery on others.