Black Willow is a fast-growing, flowering tree. Yellow-green flowers bloom April-May, providing a nectar source for native bees, honeybees, bumblebees, and beneficial predatory insects, which prey on garden pest insects. It is a host plant for butterfly and moth larvae (caterpillars), including Viceroy (Limenitis archippus), Mourning Cloak (Nymphalis antiopa), Red-spotted Purple (Limenitis arthemis), Eastern Tiger Swallowtail (Papilio glaucus), and Acadian Hairstreak (Satyrium acadica). Black Willow has attractive, deeply furrowed bark. Use it as specimen tree in moist areas around your yard, or along streambanks for erosion control.