According to observations of naturalists and beekeepers.
Where are you?
Diamondleaf willow grows from the southern Yukon Territory south to California and New Mexico, and east across boreal Canada to eastern Canada and New England. It is restricted to mountainous terrain in the western United States.
This plant is present in at least 29 states/provinces in this country.
Diamondleaf willow is a small-to-medium-sized deciduous shrub. The bark is gray and smooth. The flowers occur in about 1- to 2-inch-long (2.5 cm), erect catkins on the previous year's twigs.
Diamondleaf willow flowers appear in the spring before or sometimes with the leaves.
Acer saccharinum (aka: Silver maple, Soft maple)
Ulmus americana (aka: American elm, White elm, Water elm, Soft elm, Florida elm)
Acer negundo (aka: Boxelder, Western boxelder, Arizona boxelder, California boxelder, Texas boxelder, Interior boxelder, Violet boxelder)
Acer glabrum (aka: Rocky Mountain maple, Douglas maple, Greene's maple, New Mexico maple, Torrey maple)
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)
Crataegus douglasii (aka: Black hawthorn, Douglas hawthorn, River hawthorn, Western thornapple)
Acer saccharum (aka: Sugar maple, Rock maple, Hard maple)
Prunus americana (aka: American plum, Goose plum, River plum, Wild plum)
Populus tremuloides (aka: Quaking aspen, Trembling aspen, Aspen, American aspen, Mountain aspen, Golden aspen, Trembling poplar, White poplar, Popple, Alamo Blanco)
Salix scouleriana (aka: Scouler's willow, Upland willow)
Salix bebbiana (aka: Bebb willow, Beak willow, Beaked willow, Long-beaked willow, Diamond willow, Chaton, Petit Minou, Smooth Bebb willow)
Prunus pumila (aka: Sandcherry, Western sandcherry, Eastern sandcherry, Great Lakes sandcherry)
Salix discolor (aka: Pussy willow, American pussy willow, Glaucous willow, Large pussy willow)
Salix lutea (aka: Yellow willow)