Black hawthorn (Crataegus douglasii) is a small shrub or tree native to North America. Members of the Crataegus genus, the hawthorns, are found throughout temperate regions of the world. Popular with gardeners, hawthorn species hybridize easily making the taxonomy of this group complex.
Black hawthorn, also colloquially known as thorn apple or Douglas hawthorn, among other names, grows in moist, open places and along streamside areas, forest edges and roadways. It can be found across Canada and the northern tier of states as well as Alaska, California and Nevada.
The bark of black hawthorn is grey, rough and scaly. The twigs grow in a zig-zag manner and are armed with sharp thorns that grow to 3 cm in length. The twigs are reddish when young fading to grey as they age.
The deciduous, alternate black hawthorn leaves are dark green above and paler below. Oval in shape with five to nine small lobes at the top end, the leaves have saw-toothed margins.
The flowers are white with 5 petals, 10 to 20 stamens and look like apple blossoms. They are borne in clusters terminally or in leaf axes. The smell is fetid. Hawthorns were common in Western Pennsylvania where I grew up. So rather than finding the odor of hawthorn blossoms unpleasant, the aroma brings back strong memories of spring days wandering in the woods behind my childhood home. Bees swarm to hawthorn flowers.
The fruit is a pome and looks like a little apple, with the remains of the calyx persistent on the fruit. The drooping clusters of black hawthorn fruits are on slender stalklets. Greenish when immature, the fruits age to red and then a purple-black at maturity. The light yellow flesh is juicy, sweet and edible. I often nibble on the tiny black hawthorn “apples” while hiking even though they have five large seeds in each fruit. Birds, particularly quail, bears and other small mammals eat black hawthorn fruit.
Native Americans used hawthorn thorns as prongs on rakes for catching herring, as lances for piercing skin blisters or boils and as fish hooks. (I remember trying to fish with black hawthorn thorns as a youngster.) The wood is very hard and was used for tool handles and weapons. Several medical conditions, including venereal diseases, heart problems and swelling, were treated with concoctions made from the bark.
Especially in England, rows of hawthorn trees were used as fences or barriers. The name hawthorn comes from the Medieval Anglo-Saxon “haw” meaning hedge. The genus name, Crataegus, derives from the Greek “kratos” meaning strength because the wood of hawthorns is fine grained and strong.
This black hawthorn tree was growing near the Hat Creek Riffle (Shasta County CA).