According to observations of naturalists and beekeepers.
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Bitter cherry occurs from British Columbia and Vancouver Island south to southern California and east to Montana, Wyoming, Utah, and New Mexico.
This plant is present in at least 11 states/provinces in this country.
Bitter cherry is a native, deciduous, small tree or shrub with spreading to ascending branches. It often forms dense thickets. It generally persists as a medium to tall shrub, 3.3 to 20 feet (1-6 m) in height. With abundant moisture and deep fertile soil, bitter cherry may reach tree height: up to 50 feet (15 m) in some areas.
The leaves are 0.8 to 2 inches (2-5 cm) long and 0.4 to 1.4 inches (1-3.5 cm) wide. The drupelike, ovoid fruit is 0.24 to 0.56 inches (6-14 mm) in diameter and is one-seeded. Roots may spread up to 50 feet (15 m) from the parent plant, sending up adventitious shoots along their length. Bitter cherry has no taproot.
Bloom Period: April-June. Cherries ripen July to September, dispersal occurs August through September.
Brassica napus (aka: Rapeseed)
Allium schoenoprasum (aka: Chives)
Sinapis arvensis (aka: Charlock mustard, California rape, Charlock, Corn mustard, Canola, Kaber mustard, Rapeseed mustard)
Calendula officinalis (aka: Marigold, Calendula, Pot marigold, English marigold)
Agastache foeniculum (aka: Giant hyssop, Blue giant hyssop, Anise hyssop, Fragrant giant hyssop, Lavender giant hyssop)
Chamaenerion angustifolium (aka: Fireweed, Great willowherb, Rosebay willowherb, Saint Anthony's Laurel, French-willow)
Cucumis melo (aka: Cantaloupe, Rockmelon, Sweet melon, Spanspek, Honeydew melon, Honeymelon, Crenshaw, Casaba)
Borago officinalis (aka: Borage, Starflower, Common borage, Cool-tankard, Tailwort)
Cirsium arvense (aka: Creeping Thistle, Canada thistle, Field thistle, California thistle, Lettuce from hell thistle, Corn thistle, Cursed thistle, Green thistle, Hard thistle, Perennial thistle, Prickly thistle, Small-flowered thistle, Way thistle, Stinger-needles)
Calluna vulgaris (aka: Heather, Scotch heather, Common heather, Ling, Simply heather)