When I see some willows -
 down by water's edge,
  drooping in the moonlight,
 or swaying in the breeze -

I think of Blackwood's tale
 of Danube canoers
  who land upon an isle
  to camp among the willows.

And will the willows that
 I see, mark wicked ground,
  and what will they become
 when darkness makes its stand?

It's such a pretty tree...
 now all but ruined for me,
  and that is story's power
 to sweeten or to sour.

For those interested in reading the referenced story: