According to observations of naturalists and beekeepers.
Where are you?
NECTAR PRODUCTION:
56 - 112 kilograms per ha
SOURCE FOR HONEY BEES:
Minor
The most widespread occurrence of black hawthorn is in the Pacific Northwest, from southeastern Alaska south through British Columbia, Alberta, Washington, and Oregon to northern California. Inland distribution encompasses northern Nevada, Utah, Colorado, and Wyoming, western Montana, and Idaho. Douglas hawthorn may also be found as a disjunct in northern Michigan, Minnesota, Saskatchewan, and southern Ontario.
This plant is present in at least 18 states/provinces in this country.
Black hawthorn is a large shrub or small tree ranging from 3.5 to 13.0 feet (1-4 m) tall and possessing straight, strong thorns 0.5 to 1.0 inch (1.00-2.50 cm) long. Leaves are generally 1.5 to 2.5 inches (3-6 cm) long, broad, and serrated at the tip. Blackish, smooth fruits are about 0.5 inches (1 cm) long. Numerous mosses and lichens are present upon the entire bark system.
Black hawthorn stems are usually clustered from the base or from a point just above the soil surface. Shade-killed lower limbs persist on the stem, creating large, dense thickets. Stems are very flexible and have been shown to withstand avalanche impact pressures of up to 10 tons per square meter.
This plant is flowering from April to May.
Black hawthorn fruits are considered ripe when they are black and lustrous. In Oregon fruit was dispersed from August 16 to 31, and in Washington from July 15 to 30.
Acer saccharinum (aka: Silver maple, Soft maple)
Cercis orbiculata (aka: California redbud, Western redbud, Arizona redbud, Judas tree, Cercis occidentalis)
Rubus ursinus (aka: California blackberry, California dewberry, California grapeleaf dewberry, Douglasberry, Pacific blackberry)
Rubus spectabilis (aka: Salmonberry)
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)
Prunus andersonii (aka: Desert peach, Desert peachbush, Anderson peachbush, Wild almond)
Pyrus communis (aka: European pear, Common pear)
Salix exigua (aka: Narrowleaf willow, Coyote 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)
Aesculus californica (aka: California buckeye, Buckeye, Horsechestnut)
Acer macrophyllum (aka: Bigleaf maple, Big-leaf maple, Oregon maple)
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)
Prunus emarginata (aka: Bitter cherry)
Prunus ilicifolia (aka: Hollyleaf cherry, Holly-leaved cherry, Islay, Evergreen cherry)
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)
Salix scouleriana (aka: Scouler's willow, Upland willow)
Acer circinatum (aka: Vine maple)
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)