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.
Acer rubrum (aka: Red maple, Scarlet maple)
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)
Pyrus communis (aka: European pear, Common pear)
Aesculus californica (aka: California buckeye, Buckeye, Horsechestnut)
Rubus spectabilis (aka: Salmonberry)
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 macrophyllum (aka: Bigleaf maple, Big-leaf maple, Oregon maple)
Crataegus douglasii (aka: Black hawthorn, Douglas hawthorn, River hawthorn, Western thornapple)
Populus tremuloides (aka: Quaking aspen, Trembling aspen, Aspen, American aspen, Mountain aspen, Golden aspen, Trembling poplar, White poplar, Popple, Alamo Blanco)
Acer circinatum (aka: Vine maple)
Prunus emarginata (aka: Bitter cherry)
Prunus pumila (aka: Sandcherry, Western sandcherry, Eastern sandcherry, Great Lakes sandcherry)
Salix scouleriana (aka: Scouler's willow, Upland willow)
Malus fusca (aka: Oregon crab, Oregon crab apple, Pacific crab apple, Western crab apple)
Salix bebbiana (aka: Bebb willow, Beak willow, Beaked willow, Long-beaked willow, Diamond willow, Chaton, Petit Minou, Smooth Bebb willow)
Malus domestica (aka: Pyrus pumila, Malus pumila, Apple)
Acer platanoides (aka: Norway maple)
Rubus ursinus (aka: California blackberry, California dewberry, California grapeleaf dewberry, Douglasberry, Pacific blackberry)
Salix drummondiana (aka: Drummond's willow, Beautiful willow, Blue willow)
Salix lemmonii (aka: Lemmon's willow, Lemmon willow)
Salix boothii (aka: Booth's willow)
Salix lutea (aka: Yellow willow)
Salix planifolia (aka: Diamondleaf willow, Planeleaf willow)
Salix amygdaloides (aka: Peachleaf willow, Peach leaf willow)
Robinia pseudoacacia (aka: Black locust, False acacia, Yellow locust, White locust, Green locust, Post locust, Falsa acacia, Robinia)
Ajuga reptans (aka: Bugle, Blue bugle, Bugleherb, Bugleweed, Carpetweed, Carpet bugleweed, Common bugle, St. Lawrence plant)
Astragalus (aka: Milkvetch, Locoweed, Goat's-thorn)
Rubus laciniatus (aka: Cutleaf blackberry, Evergreen blackberry, Slashed blackberry)
Rhus glabra (aka: Smooth sumac, Common sumac, Rocky Mountain sumac, Red sumac, Western sumac, White sumac)
Salix geyeriana (aka: Geyer willow, Silver willow)
Brassica napus (aka: Rapeseed)
Allium schoenoprasum (aka: Chives)
Sinapis arvensis (aka: Charlock mustard, California rape, Charlock, Corn mustard, Canola, Kaber mustard, Rapeseed mustard)
Prunus virginiana (aka: Chokecherry, Western chokecherry, Common chokecherry, Black chokecherry)
