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)
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)
Salix gooddingii (aka: Goodding's willow, Dudley willow, Valley willow, Western black willow)
Prunus serotina (aka: Black cherry, Wild black cherry, Rum cherry, Mountain black cherry, Wild cherry)
Acer grandidentatum (aka: Bigtooth maple, Canyon maple, Western sugar maple)
Acer negundo (aka: Boxelder, Western boxelder, Arizona boxelder, California boxelder, Texas boxelder, Interior boxelder, Violet boxelder)
Robinia pseudoacacia (aka: Black locust, False acacia, Yellow locust, White locust, Green locust, Post locust, Falsa acacia, Robinia)
Celtis laevigata (aka: Hackberry, Sugarberry, Lowland hackberry, Sugar hackberry, Arizona sugarberry, Netleaf hackberry, Small's hackberry, Southern hackberry, Texas sugarberry)
Pyrus communis (aka: European pear, Common pear)
Ungnadia speciosa (aka: Mexican buckeye, Texas buckeye, Canyon buckeye, Spanish buckeye, New Mexican buckeye, New Mexico buckeye, False buckeye, Monillo, Monilla)
Celtis occidentalis (aka: Common hackberry, Bastard elm, Nettle-tree, Northern hackberry)
Ilex opaca (aka: American holly, Dune holly, Hummock holly, Scrub holly)
Malus domestica (aka: Pyrus pumila, Malus pumila, Apple)
Salix exigua (aka: Narrowleaf willow, Coyote willow)
Populus tremuloides (aka: Quaking aspen, Trembling aspen, Aspen, American aspen, Mountain aspen, Golden aspen, Trembling poplar, White poplar, Popple, Alamo Blanco)
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)
Liriodendron tulipifera (aka: Tuliptree, Blue-poplar, Tulip-poplar, Yellow-poplar, Yellow wood)