The willow is the tree of the Flats. You can find other species if you look, but it is likely that someone took a lot of trouble to bring them in and make them grow. The willow "likes to have its feet wet," as my father says. A needful thing where the highest ground is only a few feet above the surrounding water.
Almost every island in the Flats has willows. I suspect that willows are the cause of most of the larger islands in the Flats. Before people came along with sea-walls and the notion that property ought to stay put, the low silty islands in the Flats must have washed away with some regularity -- except where willows took root. The red, thread-like roots of willows can hold ground together through a few years of high water where it might wash away with only grasses, reeds and shrubs to stabilize it.
The willow is a tree that doesn't make people seem ephemeral. It is not uncommon for a person to plant a willow, see it mature, and finally see it grow old and die.
My mother, who lived until 1999, helped her father plant a row of willows along the east side of the cottage when she was a young woman. She saw most of them grow, mature, and fall. Only one is left and it needs either extreme trimming or removal. If the wind blew wrong it might fall on the new cottage.
There are only a few old willows left around the new cottage. There isn't much interest in planting new ones right now. The willow IS a dirty tree, shedding twigs and leaves all over everything in even the most modest of storms, and it gets into the drainfields of septic systems.