The Valley of the Shadow of the Gowanus, as I like to call it, is the lowland between the ridge of Brooklyn Heights and the Harbor Hill Moraine. The western slope of Park Slope and the eastern slope of Punkiesburg (Cobble Hill) used to drain down into the marshy Gowanus creek, thought to have been named after a native American by European settlers. In the colonial era, the creek and Wallabout Bay to the north pinched off Brooklyn Heights, making for a strategic passive defense for the glorious retreat of the Americans in the Battle of Brooklyn in August, 1776. The 1.5 mile Gowanus Canal, the great greasy green Gowanus, completed in 1869, turned the area into an industrial zone. Nearly a century of toxins resulted in what is now a Superfund site.But… silktrees, Albizia julibrissin, sometimes called mimosa, are blooming now on Union Street. This species is native to southern Asia from Iran to Japan. Persian silktree is another of its common name.Starting out as a big weed, the tree of heaven, Ailanthus altissima, the tree of A Tree Grows In Brooklyn. Anywhere in Brooklyn. Everywhere in Brooklyn. A native of China and Taiwan. The largest leaves in town? Royal paulownia, Paulownia tormentosa, also starts off a weedy-looking thing. Native to China and Korea.
All three of these trees were originally imported to plant in gardens and parks. They took on a life of their own, though, and have become naturalized.Ailanthus, paulownia, and silktree fighting it out at the Union Street Bridge over the canal. They are all growing out of the soil covering a fuel bunker, and squeezing through the fence.