First Known When Lost

I never had noticed it until 'Twas gone, - the narrow copse Where now the woodman lops The last of the willows with his bill It was not more than a hedge overgrown. One meadow's breadth away I passed it day by day. Now the soil is bare as bone, And black betwixt two meadows green, Though fresh-cut fag got ends Of hazel made some amends With a gleam as if flowers they had been. Strange it could have hidden so near! And now I see as I look That the small winding brook, A tributary's tributary, rises there.