According to observations of naturalists and beekeepers.
Where are you?
Black willow is found throughout the eastern United States, adjacent parts of Canada, and Mexico. Its range extends west from southern New Brunswick and central Maine to Quebec, southern Ontario, central Michigan, southeastern Minnesota, and eastern North Dakota. It occurs south and west to the Rio Grande just below its confluence with the Pecos River; and east along the Gulf Coast through the Florida Panhandle and southern Georgia. Black willow has been introduced in Utah where it is now common along many stream bottoms.
This plant is present in at least 41 states/provinces in this country.
Black willow flowering begins in February in the southern portion of its range and extends through late June at the northern limits. The catkins usually appear at the time of or immediately preceding leaf emergence. Seeds ripen and fall in April to July.
Acer saccharinum (aka: Silver maple, Soft maple)
Salix nigra (aka: Black willow, Swamp willow, Southwestern black willow, Gulf black willow, Scythe-leaved willow)
Cercis canadensis (aka: Eastern redbud, Redbud, Cersis Reniformis)
Malus angustifolia (aka: American crab apple, Buncombe crab apple, Crabtree, Narrowleaf crab, Narrowleaf crab apple, Southern crab, Southern crab apple)
Aronia arbutifolia (aka: Red chokeberry)
Ulmus americana (aka: American elm, White elm, Water elm, Soft elm, Florida elm)
Acer rubrum (aka: Red maple, Scarlet maple)
Salix discolor (aka: Pussy willow, American pussy willow, Glaucous willow, Large pussy willow)
Pyrus communis (aka: European pear, Common pear)
Acer negundo (aka: Boxelder, Western boxelder, Arizona boxelder, California boxelder, Texas boxelder, Interior boxelder, Violet boxelder)
Celtis laevigata (aka: Hackberry, Sugarberry, Lowland hackberry, Sugar hackberry, Arizona sugarberry, Netleaf hackberry, Small's hackberry, Southern hackberry, Texas sugarberry)
Salix lucida (aka: Shining willow, Greenleaf willow, Tail-leaf willow, Whiplash willow, Pacific willow, Lance-leaf willow, Longleaf willow, Red willow, Western shining willow)
Malus domestica (aka: Pyrus pumila, Malus pumila, Apple)
Prunus cerasus (aka: Sour cherry, Tart cherry, Dwarf cherry, Montmorency cherry)
Malus coronaria (aka: Sweet crab apple, Garland crab, Alabama crab, Allegheny crab, American crab, Baltimore crab apple, Buncombe crab, Dawson crab, Dunbar crab, Fragrant crab, Garland tree, Lanceleaf crab apple, Missouri crab, Sweet-scented crab, Sweet wild crab, Wild crab, Wild sweet crab, Wild Crab Apple)
Acer saccharum (aka: Sugar maple, Rock maple, Hard maple)
Populus tremuloides (aka: Quaking aspen, Trembling aspen, Aspen, American aspen, Mountain aspen, Golden aspen, Trembling poplar, White poplar, Popple, Alamo Blanco)
Liriodendron tulipifera (aka: Tuliptree, Blue-poplar, Tulip-poplar, Yellow-poplar, Yellow wood)
Prunus pumila (aka: Sandcherry, Western sandcherry, Eastern sandcherry, Great Lakes sandcherry)
Vaccinium corymbosum (aka: Highbush blueberry, High-bush blueberry, Northern highbush blueberry, Tall blueberry, Rabbiteye blueberry, Blue huckleberry, Tall huckleberry, Swamp huckleberry, High blueberry, Swamp blueberry)
Salix bebbiana (aka: Bebb willow, Beak willow, Beaked willow, Long-beaked willow, Diamond willow, Chaton, Petit Minou, Smooth Bebb willow)
Prunus americana (aka: American plum, Goose plum, River plum, Wild plum)
Ilex opaca (aka: American holly, Dune holly, Hummock holly, Scrub holly)
Acer platanoides (aka: Norway maple)