According to observations of naturalists and beekeepers.
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Grayleaf willow grows throughout most of Alaska except for the Aleutian Islands and along the southeastern coast. It grows through much of northern Canada from Newfoundland northwest to the northern Yukon Territory, and south to southern British Columbia and Alberta. In the contiguous United States, it grows in alpine and subalpine habitats in Montana, Wyoming, eastern Idaho, Colorado, Utah, and northern New Mexico.
This plant is present in at least 20 states/provinces in this country.
Grayleaf willow commonly grows as an erect shrub 3 to 4 feet (0.9-1.2 m) tall. On exposed tundra sites it grows as a low, semi prostrate shrub, and on favorable sites, it sometimes grows up to 20 feet (6 m) in height and 5 inches (12 cm) in diameter. The bark is gray and smooth but may become rough and furrowed on larger individuals.
Male and female flowers occur on separate plants in 3/4- to 2-inch-long (2-5 cm) catkins that persist over the summer.
The fruit is a 1/32- to 1/16-inch-long (0.8-1.6 mm) two-valved capsule.
Grayleaf willow catkins appear with the leaves. In Alaska and the Yukon, flowering generally occurs in June, the fruits ripen in July and August and the seeds are dispersed in late August and September.
Ulmus americana (aka: American elm, White elm, Water elm, Soft elm, Florida elm)
Salix gooddingii (aka: Goodding's willow, Dudley willow, Valley willow, Western black willow)
Prunus armeniaca (aka: Armenian plum, Ansu apricot, Siberian apricot, Tibetan apricot, Apricot tree)
Salix nigra (aka: Black willow, Swamp willow, Southwestern black willow, Gulf black willow, Scythe-leaved willow)
Celtis laevigata (aka: Hackberry, Sugarberry, Lowland hackberry, Sugar hackberry, Arizona sugarberry, Netleaf hackberry, Small's hackberry, Southern hackberry, Texas sugarberry)
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)
Salix exigua (aka: Narrowleaf willow, Coyote willow)
Acer grandidentatum (aka: Bigtooth maple, Canyon maple, Western sugar maple)
Prunus cerasus (aka: Sour cherry, Tart cherry, Dwarf cherry, Montmorency cherry)
Prunus pumila (aka: Sandcherry, Western sandcherry, Eastern sandcherry, Great Lakes sandcherry)
Salix scouleriana (aka: Scouler's willow, Upland willow)
Celtis occidentalis (aka: Common hackberry, Bastard elm, Nettle-tree, Northern hackberry)
Salix discolor (aka: Pussy willow, American pussy willow, Glaucous willow, Large pussy willow)
Malus domestica (aka: Pyrus pumila, Malus pumila, Apple)
