15 Hawthorn Tree Types: Crataegus Myths, Facts & Growing Guide

Kim Williamson, Author 8 Billion TreesWritten by Kim Williamson

Forestry, Trees and Tree Planting | February 26, 2024

Close up image of a hawthorn tree flower group with white flowers and pink dots illustrating various types of hawthorn tree (crataegus) species.

Hawthorn Trees are easily recognizable by their red, berry-like fruit, white, malodorous flowers, and thorny bark, but it is especially difficult to distinguish one Hawthorn species from another.

These trees have been planted in hedgerows for hundreds of years, but their cultural significance dates back much further.

This article explores the facts and myths surrounding Hawthorn Trees, examines 15 of the most prominent Hawthorn Tree species, and offers a complete growing guide so that you can start your own Hawthorn tree tradition.

Hawthorn Tree Facts

When people refer to Hawthorn Trees, they are usually talking about the genus, Crataegus, which is composed of hundreds of species of flowering shrubs and small trees. Hawthorns are abundant with representatives worldwide.

They grow in a wide range of environments, tolerating rural and urban landscapes equally well. Although these trees are extremely common, their historical significance is anything but.

Hawthorns

(Crataegus)

Hawthorn Tree in oval frame on green background.
  • Characteristics: Crataegus is a genus composed of hundreds of species of deciduous, flowering shrubs to mid-size trees. Hawthorns are prominent in the northern hemisphere with at least 70 species in eastern North America alone.
  • Order: Rosales
  • Family: Rosaceae
  • Type: Deciduous
  • Leaf: Simple. Alternate. Deeply lobed, sharp-toothed or serrated.
  • Bark: Bark may be smooth or scaly. Sometimes thorny along the trunk and usually thorny on the branches. Thorns may grow up to 5 inches long.
  • Blossoms: Monoecious. Typically white, sometimes pale pink to red. Flowers have 5 petals, 5 blossoms and up to 20 stamens. The small blossoms grow in corymbs. Insect-pollinated. Sulphur smell.
  • Fruit: Small pome resembling a berry, called a “haw.” Pomes hang in drooping clusters. Fruits are often dark red or orange when ripe, containing 1 to 5 seeds, depending on species.
  • Seed: Small, hard-shelled.
  • Growth Rate: Slow to moderate. Less than 2 feet per year.
  • Average Life Span: Several hundred years.
  • Height: 10 to 30 feet on average.
  • Canopy: Dense, wide-spreading canopies often equal to the tree’s height. Rounded, open crown.
  • Native Habitat: Eastern U.S. Flourishes in open areas such as hillsides, roadsides and forest edges.
  • USDA Growing Zone: 4 - 7

Here are a few Hawthorn Tree facts of interest:

  1. The genus, Crataegus, (derived from the Greek ‘Kratos’ meaning strong) was officially recognized in 1753.
  2. Another closely related genus, Rhaphiolepis, has several species commonly referred to as Hawthorns.
  3. The berry-like fruit of the Hawthorn Tree is often called a “haw.”
  4. Hawthorn fruits are edible and are sometimes cooked for use in tea, jelly, and wine. The seeds, however, are not recommended for consumption as they contain small amounts of cyanide.21
  5. Native European species such as the English Hawthorn have been used in hedging for hundreds of years. In fact, Hawthorn Trees were such a prominent feature of the European landscape that they caused some interference with the 1944 Invasion of Normandy in World War II.10
  6. Hawthorn has long been used in remedies for cardiovascular ailments, such as high blood pressure, as it has demonstrated effectiveness in increasing blood flow and circulation.10
  7. The leaves of Hawthorn Trees can be used as a nicotine-free alternative to tobacco.14
  8. The fruit of Hawthorn Trees is important in the diet of small animals such as birds, squirrels, and raccoons as well as larger mammals such as deer.9

Hawthorn Tree Symbolism

There is much lore and symbolism surrounding Hawthorn Trees, dating back more than 2,000 years. The primary Hawthorn Tree symbolism stems from the story of Joseph of Arimathea, a follower of Jesus Christ who was believed to have buried Jesus’ body after death.

Legends state that Joseph traveled to Britain bearing the blood and sweat of Jesus and that he plunged his walking staff into the ground atop a hill where it took root before morning.

The resulting tree, Crataegus monogyna ‘Biflora’, became known as the Miraculous Tree and the “Holy Thorn of Glastonbury.” It was revered and believed to have supernatural powers, and some associate it with the rise of Christianity in Britain.

Descendants of the original Hawthorn Tree still grow in Glastonbury today.16

Hawthorns also feature in Celtic and Gaelic mythology, as they were believed to house faeries. Subsequently, Hawthorns were held sacred and protected from damage.11

In medieval times, the unpleasant odor of the Hawthorn flowers was thought to portend death and bring ill luck.11

Hawthorn Tree Identification (How To Identify Hawthorn Tree)

The key to learning how to identify Hawthorn Trees lies particularly in the examination of qualities unique to members of the Crataegus genus.

Hawthorn Trees have a few distinctive features, such as their simple, lobed, or toothed leaves, malodorous flowers, hard-shelled seeds in an apple-like fruit (pome), and slender, unbranched thorns.24

Hawthorn Tree Identification chart showing full-grown leaves, flowers, seed pod and bark.

Since it is quite possible to mistake a small Hawthorn Tree for a poisonous bush with red berries, identification using various plant traits is recommended.

Furthermore, Crataegus species are particularly difficult to differentiate, possibly due to sexual reproduction and hybridization over time.18

It is usually necessary to examine multiple parts of a single Hawthorn Tree during the active season to determine the exact species.25 The following sections look at some of the most recognizable characteristics of Hawthorn Trees.

Hawthorn Tree Leaves

The many species of Hawthorns have a wide range of leaf characteristics. In some species, such as C. monogyna and C. orientalis, the leaves are deeply cut with 5 or more lobes.

Other species, such as C. crus-galli have oval leaves which draw to a point and have serrated or sharp-toothed margins.24 All Hawthorn Tree leaves are simple (not compound), arranged alternately, and deciduous.25

Hawthorn Tree Flower

The insect-pollinated flowers of the Crataegus genus are rather similar to those of Apple Trees and Pear Trees. In most species, the flowers are symmetrical, small, and white, though some cultivars have pink or red flowers.

Closeup of Hawthorn Tree showing clusters of tiny flowers with five white petals.

(Image: Fredpichon28)

Each blossom has 5 petals and 5 sepals.18 They bloom in May and are known to emit a sulfurous smell that is not equally prominent across species.

Hawthorn Tree flowers have also been noted to produce purple pollen. Multiple flowers are typically clustered on umbels or corymbs.24

Hawthorn Berries (Fruit)

The Hawthorn berries are one of the trees’ most recognizable qualities, but unlike the fruits of the Mulberry Tree, Hawthorn fruits are actually not berries at all but are, in fact, more similar to apples. (Read more about red berry tree identification here.)

The “haw,” or fruit of the Hawthorn Tree, is a small, fleshy pome housing between one and five small seeds.18,24 The ripe fruit is usually a vivid red but may be brown or black in certain species.

The ‘berries’ are beloved by small animals, birds in particular, and insects. Hawthorn fruit has been used for culinary and medicinal purposes.13

Hawthorn Tree Seeds

Hawthorn Tree seeds are small and hard-shelled.24 They typically appear in groups of 2 to 5 seeds per fruit, though some species have single-seeded fruit.25

While the fruit of the Hawthorn Tree is edible and generally palatable, the seeds are poisonous and should not be consumed.

Types of Hawthorn Trees

Crataegus is a very large genus made up of hundreds of different species of trees. With its 5-petaled flower clusters, small, red fruit resembling tiny apples, and thorny bark and branches, it is a fairly easy group of trees to identify.

However, it can be much more challenging to differentiate between the various types of Hawthorn Trees. This section explores many of the most common, prominent, and interesting species of Hawthorn Tree with emphasis on North American natives.

1. Black Hawthorn or Douglas Hawthorn (Crataegus douglasii)

The Black Hawthorn is native to North America and is most common in the northwestern region of the United States. It grows well in moist areas and wetlands but is tolerant of many topographies.

Closeup of Black Hawthorn Tree showing cluster of lobed leaves with white flowers blooming in the center.

(Image: Nadiatalent29)

This species reaches maximum heights of about 25 feet, but it has been known to produce suckers from the base of the trunk allowing it to spread outward. This species’ common name derives from its black, 5-seeded fruit, which sets it apart from other Hawthorns.9

Close up of a cluster of Chinese Hawthorn flowers with its white petals on a stem.

(Image: 阿橋 HQ31)

2. Chinese Hawthorn (Crataegus pinnatifida)

The Chinese Hawthorn is one of the few non-native species on this list. It is unique to the Hawthorn genus because it has significantly fewer and smaller thorns.

The sweet and sour sauce common in many Chinese dishes uses the fruit of Crataegus pinnatifida as an ingredient.12

3. Cockspur Hawthorn (Crataegus crus-galli)

The Cockspur Hawthorn is usually found in the Eastern U.S. growing as far north as Vermont and as far south as Texas. It’s small (.5”), and white flowers grow in corymbs.

Closeup of Cockspur Hawthorn Tree showing foliage with lots of leave and berry-like red fruits.

(Image: Hans28)

It has unlobed, ovate leaves with fine-toothed margins, and a slightly pointed leaf tip. The glossy, mature leaves can be as long as 4 inches and may turn to a bronze or purple-red color in the fall.

The Cockspur fruits in October, and the greenish-red fruit is about .5 inches in diameter. Crataegus crus-galli tolerates hot, dry climates well.1

It can be recognized by its long, straight, slender, and stiff thorns which grow to 4 inches on branches and longer along the trunk.26

Closeup of Common Hawthorn Tree showing budding and blooming white flowers.

(Image: beauty_of_nature28)

4. Common Hawthorn (Crataegus monogyna)

The Common Hawthorn is native to Europe,11 West Asia, and North Africa, but it is naturalized across the U.S. This Hawthorn Tree is remarkable in that its fruit is single-seeded and its lobed leaves are deeply cut.

One variety, Crataegus monogyna ‘Biflora’, the Glastonbury Thorn or Holy Thorn is sometimes called “the Miraculous Tree,” due to its association with the death of Christ and the rise of Christianity in Europe. The tree flowers twice annually in the spring and at Christmas time and has survived through cuttings, offshoots, and saplings.

It has become associated with new-age pagan religions in recent years.15

5. Dotted Hawthorn or Large-Fruited Hawthorn (Crataegus punctata)

Native to the Southern Appalachian Region of the United States, the Dotted Hawthorn is a small tree that thrives in wooded areas with rich soils and along streams.

Its leaves, which are double-toothed and shallowly lobed grow up to 10 cm in length. Crataegus punctata is not one of the thornier Hawthorn varieties, but it may have slender thorns up to 7 cm long.

Closeup of Dotted Hawthorn Tree showing serrated-edged leaves and a cluster of small white flowers.

(Image: Nadiatalent29)

It is sometimes called the Large-Fruited Hawthorn as its yellow to brown dotted fruit may double the size of many other Hawthorns (up to 20 mm in diameter!).25

Top shot of Downy Hawthorn Tree branch showing leaves and with white flowers.

(Image: Nadiatalent29)

6. Downy Hawthorn or Red Haw (Crataegus mollis)

The Red Haw Tree is among the most common Hawthorn species in the Eastern U.S., stretching from New York down to Alabama and into the north-central region of the country.

The Red Haw Tree grows a bit larger than many Hawthorns, reaching heights of up to 40 feet. It blooms early, with flower blossoms somewhat bigger than many Hawthorn species (up to 1 in.).

Crataegus mollis fruits appear fairly early in the fall, with apple-like pomes approximately .5” in diameter. Also called the Downy Hawthorn, it can also be distinguished by its wooly flowers and leaves and its nearly thornless bark.26

7. English Hawthorn (Crataegus laevigata)

This small Hawthorn variety native to Europe, India, and North Africa has a dense, rounded canopy, thorny branches, and glossy, green leaves with 3 to 5 shallow lobes. A single corymb may contain as many as 12 white to light pink blooms.

Closeup of English Hawthorn Tree showing blooming white flowers.

(Image: Jan Helebrant30)

This species is vulnerable to rust, leaf spot, and blight, but the English Hawthorn also has a ‘Crimson Cloud’ variety which bears red flowers and is more disease resistant.2,10

Closeup of Fireberry Hawthorn Tree showing lobed leaves and small white flowers.

(Image: Nadiatalent29)

8. Fireberry Hawthorn (Crataegus chrysocarpa)

The Fireberry Hawthorn is common in the north-central region of the U.S. This aptly named Hawthorn Tree produces vivid red fruit which darkens to crimson when ripe.

It grows as a multi-stemmed shrub unless trained into a single-trunked tree. The flower stalks of the Fireberry Hawthorn are usually adorned with soft hairs.

The leaves are variably lobed and toothed.27

9. Harbison’s Hawthorn (Crataegus harbisonii)

Harbison’s Hawthorn is one of the most interesting Hawthorn species as it was believed for many years to be extant as the sole surviving organism in Nashville, Tennessee. Recently, a population of Crataegus harbisonii was discovered in Tennessee outside of Nashville.

Closeup of Harbison's Hawthorn Tree showing serrated-edged leaves and budding and blooming white flowers.

(Image: U.S. DEPARTMENT OF AGRICULTURE32)

The tree remains on the endangered species list.

Closeup of Parsley Hawthorn Tree showing parsley-like leaves and white flowers.

(Image: Chris M Morris33)

10. Parsley Hawthorn (Crataegus marshallii)

This North Carolina native Hawthorn is among the loveliest of the Hawthorn Trees with its dainty flowers and intricate foliage. Its common name is derived from its parsley-shaped leaves which have 5 to 7 lobes and serrated edges.1

11. Pennsylvania Hawthorn (Crataegus pennsylvanica)

The Pennsylvania Hawthorn grows exclusively in the Eastern U.S. and Canada and prefers upland areas to wetlands. Though the IUCN lists this species as data deficient, other sources indicate that the species is vulnerable to possible extinction.3

Closeup of Pennsylvania Hawthorn Tree showing lobed leaves with serrated edges and young green Hawthorn Tree fruits.

(Image: Krzysztof Ziarnek, Kenraiz34)

The leaves of Crataegus pennsylvanica are sharply toothed and shallowly lobed, and young leaves are often hairy.16

Closeup of River Hawthorn Tree showing budding and blooming flowers and green leaves.

(Image: Tweeber29)

12. River Hawthorn (Crataegus rivularis)

The River Hawthorn is most often found in the southwestern states of the United States, particularly Colorado, and southward into Mexico. It flourishes when it grows in the valleys between mountains.22

13. Scarlet Hawthorn (Crataegus coccinea)

Scarlet Hawthorn grows from Quebec and Ontario southward as far as Kentucky. Its leaves are lobed and roughly toothed.

The green summer foliage darkens to a reddish-purple color in the fall.

Closeup of Scarlet Hawthorn Tree showing a cluster of reddish-pink fruits and dark green leaves.

(Image: 4028mdk0935)

This species is also known to bear red buds through the winter.4,5

14. Washington Hawthorn Tree (Crataegus phaenopyrum)

Closeup of Washington Hawthorn Tree showing branches with fruits and few yellowish-green leaves.

(Image: angmf4228)

The Washington Hawthorn Tree can be found throughout the Eastern U.S. as an exceedingly popular landscape tree.

It typically has 3-lobed leaves with toothed margins and a heart-shaped base, growing up to 2 inches long. Crataegus phaenopyrum is notable for its slightly curving thorns, its scarlet orange fall foliage, and its bold red fruit which lasts into winter.1

It is one of the more beautiful Hawthorn species and it has been cultivated in several European countries.26

15. Winterking Hawthorn Tree (Crataegus viridis ‘Winter King’)

Crataegus viridis, or the Green Hawthorn, is native to the Eastern United States as far south as Texas and west as Iowa.

The Winterking Hawthorn Tree is the most popular cultivar of the Green Hawthorn. Introduced in 1955, ‘Winter King’s’ improved flower and fruit displays quickly made it the cultivar of choice among Green Hawthorn varieties.

Closeup of Winterking Hawthorn Tree showing serrated-edged leaves and white flowers.

(Image: David J. Stang36)

It is made harder by grafting onto the rootstock of Washington Hawthorn Trees.19

What Is the Indian Hawthorn Tree (Rhaphiolepis indica)?

The Indian Hawthorn Tree is a species in the genus, Rhaphiolepis, which shares the same subtribe as Crataegus and is closely related. Despite their close taxonomic classification, the Indian Hawthorn Tree does not resemble the Hawthorn Trees most people are familiar with.

The Indian Hawthorn is an evergreen shrub which grows up to 6 feet tall. The flowers resemble those of Hawthorn Trees, but their berries are bluish rather than red.

The evergreen leaves may darken to purple in the winter.

Planting Tips for Hawthorn Tree

Whether an individual is interested in growing a Hawthorn Tree as ornamental or growing many trees or shrubs to create privacy hedging, it is useful to consider some basic planting tips for Hawthorn Trees. Hawthorn Trees thrive in full sun conditions, particularly when they are planted in semi-acidic, well-draining soil.20

Consider planting a thornless and disease-resistance cultivar.

Related Reading: 20 Best Privacy Trees: Fast Growing, Year Round, Growing Zones, Care Tips

How Far Apart To Plant Hawthorn Tree

To fully appreciate an individual Hawthorn Tree, it’s important to space trees apart adequately, allowing for 20 feet between trees. However, advice on how far apart to plant Hawthorn Trees changes when the trees are being used to create a hedgerow.

In this scenario, don’t allow for more than a few feet between each plant.17,19

When To Plant Hawthorn Tree for the Best Yield

Anyone curious about when to plant Hawthorn Tree for the best yield should plan to put their Hawthorn Trees in the ground in the spring so that they have plenty of time to transition and get adjusted before the winter season.2

Growing a Hawthorn Tree From a Seedling

Growing a Hawthorn Tree from a seedling or as a grafted tree is probably the easiest way to go. These methods give the tree a jump start, allowing the gardener to enjoy flowering and fruiting sooner.

Furthermore, grafted trees have the added benefit of increased disease resistance.

Transplant the seedling in spring in a hole the same depth and twice the diameter of the rootball. Fill the hole halfway and water intensively.

When all the water is absorbed, fill the remainder of the hole with soil. New trees should be watered regularly for the first growing season.23

Best Growing Conditions for Hawthorn Tree

Established Hawthorn Trees are extremely low maintenance and hardy, but the best-growing conditions for Hawthorn Trees depend on the species as some prefer wetlands to uplands and vice versa.

Hawthorn Tree situated in a forest showing foliage with clusters of blooming flowers.

(Image: Osioni29)

In general, though, Hawthorn Trees can thrive almost anywhere, even in small urban spaces as long as they receive enough sunlight.

Hawthorn Tree Growing Zone (Growing Zones for Hawthorn Tree: Where To Grow)

The growing zones for Hawthorn Tree (where to grow) are USDA zones 4 – 7, meaning that Hawthorn Trees are hardy to temperatures as low as -30 degrees Fahrenheit. Most of the Hawthorn Tree growing zones extend throughout the central U.S. (see USDA Plant Hardiness Zone Map).

Watering Needs for Hawthorn Tree Plants

Hawthorn Trees are fairly low maintenance in most respects. Meeting the watering needs for Hawthorn Tree plants is usually easy, as new transplants require only periodic watering for a few months until established.1

Beyond that point, young Hawthorn Trees should be watered only during dry periods, as excess water can compromise their integrity.

How Long It Takes To Grow Hawthorn Tree

A common concern about these plants is how long it takes to grow Hawthorn Trees. Hawthorn Trees are generally slow-growing.

A tree grown from a seed can take as long as 8 years to begin bearing fruit. Growing a grafted tree is quicker and can produce flowers and fruit within 3 years.12

Companion Plants for Growing Hawthorn Tree

The best companion plants for growing Hawthorn Trees are usually other small, fruiting, or flowering trees such as Plum Tree, Crabapple Tree, Serviceberry Tree, and Dogwood Tree.29 Avoid planting near large trees which will grow to create excessive shade.

Hawthorn Tree Disease Prevention (How To Stop Hawthorn Tree Disease)

In order to find out how to stop Hawthorn Tree disease, gardeners must first be familiar with the diseases known to affect this group of trees. The most problematic diseases for Hawthorns are Cedar-Hawthorn Rust (caused by the fungus Gymnosporangium globosum) and Fire Blight (caused by the bacterium Erwinia amylovora).5

Cedar-Hawthorn Rust, which causes yellow spots and foliage loss, is usually controlled through fungicides and the removal of infected wood. Hawthorn Trees are extremely susceptible to fire blight, a bacterial disease that causes the tree to appear scorched.

While excessive pruning and fertilization can make the trees more vulnerable to disease, eliminating diseased parts of the tree is crucial.9

Gardeners can select cultivars that are resistant to disease, and Hawthorns are often grown via grafting onto disease-resistant rootstock. Adequate spacing and limiting pruning to the dormant season are also critical to Hawthorn Tree disease prevention.1

Is Growing Hawthorn Tree From a Seed Difficult?

Growing Hawthorn Tree from a seed is not necessarily difficult, but it is a lengthy process. After collecting the number of seeds desired (this is the easy part), the seeds should be put in a pot with ascending layers of stones, sand, and a 1:1 ratio of horticultural sand and peat-free compost.

The seeds must remain in this pot in a shady outdoor spot for 18 months before they will germinate!12

Common Pests of the Hawthorn Tree

Hawthorn Trees attract many delightful bird species, such as bluejays and Cedar Waxwings, and they also attract butterflies. Unfortunately, some unsavory visitors may also be drawn to Hawthorn Trees.

Some common pests of the Hawthorn Tree include:8

  • Lace bugs
  • Aphids
  • Scale
  • Hawthorn leaf miners
  • Japanese beetles
  • Tent caterpillars
  • Pear slugs

Natural Pest Control for Hawthorn Tree

Natural pest control for Hawthorn Trees is not always possible, but sometimes it is! Robust, healthy trees are less likely to be infested with pests, so ensure the tree has adequate space and sunlight.

Biological controls, such as releasing natural pest enemies, can be extremely effective, but this method has its own obvious challenges.6

The many varieties of Hawthorn Trees make for an interesting study, from the legends and lore surrounding them to their practical, medicinal, and aesthetic value.

By understanding the facts about the Crataegus genus, and gaining knowledge about how to grow these trees and their varieties, you can ensure that any Hawthorn tree that you plant will thrive for years to come.

Frequently Asked Questions About Hawthorn Tree

How Much Sunlight Does Hawthorn Tree Need Each Day?

A gardener might need to know how much sunlight does Hawthorn Tree need each day. Hawthorns flourish when they can receive full sun for 6 to 8 hours each day.

Is Growing a Hawthorn Tree From a Cutting Possible?

Growing a Hawthorn Tree from a cutting is not only possible but it is one of the best ways to propagate Hawthorns at home. Cuttings placed in the right medium will usually take root in a month or less.7

Read More About Hawthorn Tree

References

1John Wiley & Sons Inc. (2012). Flowering Trees & Shrubs [Print]. Better Homes & Gardens.

2Carroll, J. (2021, June 22). Types Of Hawthorn Trees: How To Grow Hawthorn In The Landscape. Gardening Know How. Retrieved May 12, 2023, from <https://www.gardeningknowhow.com/ornamental/trees/Hawthorn/growing-Hawthorn-trees.htm>

3IUCN. (2023). crataegus. IUCN Red List. Retrieved May 12, 2023, from <https://www.iucnredlist.org/search?query=crataegus&searchType=species>

4Missouri Botanical Garden. (2023). Crataegus coccinea. Missouri Botanical Garden. Retrieved May 12, 2023, from <https://www.missouribotanicalgarden.org/PlantFinder/PlantFinderDetails.aspx?taxonid=286487>

5National Science Foundation. (2023). Crataegus coccinea — scarlet hawthorn. Native Plant Trust | Go Botany. Retrieved May 12, 2023, from <https://gobotany.nativeplanttrust.org/species/crataegus/coccinea/>

6Damask, T. (2012, November 24). Infestation of a Hawthorn Tree. Week&. Retrieved May 12, 2023, from <https://www.weekand.com/home-garden/article/infestation-Hawthorn-tree-18005748.php>

7Degnan, S. (2021, July 9). How to Grow Hawthorn Cuttings. eHow. Retrieved May 12, 2023, from <https://www.ehow.com/how_10067191_grow-hawthorn-cuttings.html>

8Dove, T., & Woolridge, G. (2018). Essential Native Trees and Shrubs for the Eastern United States: The Guide to Creating a Sustainable Landscape [Print]. Charlesbridge.

9Dyer, M.H. (2012, December 10). Hawthorne Tree Facts. Week&. Retrieved May 12, 2023, from <https://www.weekand.com/home-garden/article/Hawthorne-tree-18066199.php>

10YALE UNIVERSITY PRESS. (2015, May 1). HAWTHORN – 10 FACTS ABOUT ONE OF OUR OLDEST PLANT COMPANIONS. Yale University Press London. Retrieved May 12, 2023, from <https://yalebooksblog.co.uk/2015/05/01/Hawthorn-10-facts-about-one-of-our-oldest-plant-companions/>

11Trees for Life. (2023). Mythology and folklore of hawthorn. Trees for Life. Retrieved May 12, 2023, from <https://treesforlife.org.uk/into-the-forest/trees-plants-animals/trees/Hawthorn/>

12The Conservation Volunteers and Andy Smith. (2023). How to grow Hawthorn. TCV. Retrieved May 12, 2023, from <https://treegrowing.tcv.org.uk/grow/tree-recipes/Hawthorn>

13The Conservation Volunteers and Andy Smith. (2023). How to identify Hawthorn. TCV. Retrieved May 12, 2023, from <https://treegrowing.tcv.org.uk/identify/Hawthorn>

14Sue & Candace. (2023). Hawthorn: The Heart Healer. The Practical Herbalist. Retrieved May 12, 2023, from <https://thepracticalherbalist.com/advanced-herbalism/herbal-encyclopedia/Hawthorn-the-heart-healer/>

15Hobbs, K., & West, D. (2020). The Story of Trees: And How They Changed the World [Print]. Laurence King Publishing.

16University of Reading. (2023). The Holy Thorn. University of Reading. Retrieved May 12, 2023, from <https://research.reading.ac.uk/glastonburyabbeyarchaeology/myths/the-holy-thorn/>

17Site Staff. (2021, July 21). How Far Apart To Plant Hawthorn Shrubs For A Hedge. GardenTabs. Retrieved May 12, 2023, from <https://gardentabs.com/how-far-plant-Hawthorn-shrubs-hedge/>

18Kirkman, L. K., Leopold, D. J., & Brown, C. L. (2007). Native trees of the Southeast : [an identification guide] [Print]. Timber Press.

19Nardozzi, C. (2022). How to Grow: Hawthorn. Gardening With Charlie Nardozzi. Retrieved May 12, 2023, from <https://www.gardeningwithcharlie.com/grow-Hawthorn/>

20Neveln, V. (2023, January 24). How to Plant and Grow Hawthorn Tree. Better Homes & Gardens. Retrieved May 12, 2023, from <https://www.bhg.com/gardening/plant-dictionary/tree/Hawthorn/>

21Peterson, L. (1978). A Field Guide to Edible Wild Plants of Eastern and Central North America [Print]. Houghton Mifflin.

22Phipps, J. B. (2020, November 5). Crataegus rivularis. Flora of North America. Retrieved May 12, 2023, from <http://floranorthamerica.org/Crataegus_rivularis>

23GARDENING CHANNEL. (2023). How to Grow Hawthorn Trees. Gardening Channel. Retrieved May 12, 2023, from <https://www.gardeningchannel.com/how-to-grow-Hawthorn-trees/>

24Rix, M., & Phillips, R. (2002). The Botanical Garden: Trees and shrubs [Print]. Firefly Books.

25Swanson, R. E. (1994). A Field Guide to the Trees and Shrubs of the Southern Appalachians [Print]. Johns Hopkins University Press.

26Wharton, M. E. (1973). Trees & shrubs of Kentucky [Print]. University Press of Kentucky.

27MinnesotaWildflowers.info. (2023). Crataegus chrysocarpa (Fireberry Hawthorn). MinnesotaWildflowers.info. Retrieved May 12, 2023, from <https://www.minnesotawildflowers.info/shrub/fireberry-hawthorn>

28Hawthorn Flowers by Fredpichon, Cockspur Hawthorn by Hans, Common Hawthorn by beauty_of_nature, and Washington Hawthorn by angmf42. Retrieved from <https://pixabay.com/>

29Black Hawthorn, Dotted Hawthorn, Downy Hawthorn, Fireberry Hawthorn by Nadiatalent, River Hawthorn by Tweeber, Hawthorn Tree by Osioni. Retrieved from <https://commons.wikimedia.org/wiki/Main_Page>

30Crataegus laevigata Photo by Jan Helebrant / CC0 1.0 Universal (CC0 1.0) Public Domain Dedication. Resized and Changed Format. From Flickr <https://flic.kr/p/2nbMc7v>

31阿橋 HQ. Attribution-ShareAlike 2.0 Generic (CC BY-SA 2.0). Changed Format, Resized. Flickr. Retrieved from <https://flic.kr/p/f4nh7R>

32U.S. DEPARTMENT OF AGRICULTURE. USDA website. Retrieved from <https://www.usda.gov/media/blog/2021/06/17/unknown-population-rare-endangered-tree-discovered>

33Chris M Morris. Attribution 2.0 Generic (CC BY 2.0). Changed Format, Resized. Flickr. Retrieved from <https://flic.kr/p/82TWmz>

34Crataegus pennsylvanica Photo by Krzysztof Ziarnek, Kenraiz. Attribution-ShareAlike 4.0 International (CC BY-SA 4.0). Changed Format, Resized. Wikimedia Commons. Retrieved from <https://commons.wikimedia.org/wiki/File:Crataegus_pennsylvanica_kz01.jpg>

35Früchte des Scharlachdorn Photo by 4028mdk09. Attribution-ShareAlike 3.0 Unported (CC BY-SA 3.0). Changed Format, Resized. Wikimedia Commons. Retrieved from <https://commons.wikimedia.org/wiki/File:Fr%C3%BCchte_des_Scharlachdorn.JPG>

36Crataegus viridis Winter King Photo by David J. Stang. Attribution-ShareAlike 4.0 International (CC BY-SA 4.0). Changed Format, Resized. Wikimedia Commons. Retrieved from <https://commons.wikimedia.org/wiki/File:Crataegus_viridis_Winter_King_9zz.jpg>

37Species Information Image: A tree with red flowers Photo by Griffin Quinn. (2022, August 1) / Unsplash License. Cropped and added text, shape, and background elements. Unsplash. Retrieved February 26, 2024, from <https://unsplash.com/photos/a-tree-with-red-flowers-3VtQp8n4Nfs>