Crataegus

Read about Crataegus in the Standard Cyclopedia of Horticulture
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? Crataegus
Common Hawthorn (Crataegus monogyna)
Plant Info
Scientific classification
Kingdom: Plantae Division: Magnoliophyta Class: Magnoliopsida Order: Rosales Family: Rosaceae Subfamily: Maloideae Genus: Crataegus Tourn. ex L.
Species
See text

Crataegus (Hawthorn) is a large genus of shrubs and trees in the family Rosaceae, native to temperate regions of the Northern Hemisphere in Europe, Asia and North America. The name hawthorn was originally applied to the species native to northern Europe, especially the Common Hawthorn C. monogyna, and the unmodified name is often so used in Britain and Ireland. However the name is now also applied to the entire genus, and also to the related Asian genus Rhaphiolepis.

Common Hawthorn (close up of flowers)

They are shrubs and small trees growing to 5-15 m tall, characterized by their small pome fruit and thorny branches. The bark is smooth grey in young individuals, developing shallow longitudinal fissures with narrow ridges in older trees. The fruits are sometimes known as "haws", from which the name derived. The thorns grow from branches, and are typically 1-3 cm long. The leaves grow spirally arranged on long shoots, and in clusters on spur shoots on the branches or twigs. The leaves themselves have lobed or serrate margins and are somewhat variable shape.

The number of species in the genus depends on taxonomic interpretation, with numerous apomictic microspecies; some botanists recognise a thousand or more species, while others reduce the number to 200 or fewer.

Hawthorns provide food and shelter for many species of birds and mammals, and the flowers are important for many nectar-feeding insects. Hawthorns are also used as food plants by the larvae of a large number of Lepidoptera species — see list of Lepidoptera which feed on Hawthorns.

Many species and hybrids are used as ornamental and street trees. The Common Hawthorn is extensively used in Europe as a hedge plant. Several cultivars of the Midland Hawthorn C. laevigata have been selected for their pink or red flowers. Hawthorns are among the trees most recommended for water-conservation landscapes.

Selected species

Crataegus aemula - Rome Hawthorn Crataegus aestivalis - May Hawthorn Crataegus altaica - Altai Hawthorn Crataegus ambigua - Russian Hawthorn Crataegus ambitiosa - Grand Rapids Hawthorn Crataegus anamesa - Fort Bend Hawthorn Crataegus ancisa - Mississippi Hawthorn Crataegus annosa - Phoenix City Hawthorn Crataegus apiifolia - Parsley-leaved Hawthorn Crataegus apiomorpha - Fort Sheridan Hawthorn Crataegus aprica Crataegus arborea - Montgomery Hawthorn Crataegus arcana - Carolina Hawthorn Crataegus arkansana - Arkansas Hawthorn Crataegus arnoldiana Crataegus arrogans - Dixie Hawthorn Crataegus ater - Nashville Hawthorn Crataegus austromontana - Valley Head Hawthorn Crataegus azarolus - Azarole Hawthorn Crataegus biltmoreana Crataegus boyntonii Crataegus brachyacantha Crataegus calpodendron - Black Hawthorn Crataegus canbyi Crataegus champlainensis Crataegus chlorosarca Crataegus chrysocarpa Crataegus coccinoides Crataegus collina Crataegus columbiana Crataegus compta Crataegus crus-galli - Cockspur Thorn Crataegus cuneata - Japanese Hawthorn Crataegus cupulifera Crataegus dahurica Crataegus diffusa Crataegus douglasii - Black Hawthorn Crataegus dsungarica Crataegus dunbarii Crataegus ellwangeriana Crataegus erythropoda Crataegus flabellata Crataegus flava - Yellow-fruited Hawthorn

Crataegus fontanesiana Crataegus heldreichii Crataegus henryi Crataegus heterophylla - Various-leaved Hawthorn Crataegus holmesiana Crataegus hupehensis Crataegus intricata - Thicket Hawthorn Crataegus jackii Crataegus jonesiae Crataegus laevigata (syn. C. oxyacantha) - Midland Hawthorn- English Hawthorn Crataegus lavallei (C.Carrierei)- Carriere Hawthorn Crataegus mackenzii Crataegus macrosperma Crataegus marshalli - Parsley-leaved Hawthorn Crataegus maximowiczii Crataegus mercerensis Crataegus missouriensis Crataegus mollis - Downy Hawthorn Crataegus monogyna - Common Hawthorn Crataegus nigra - Hungarian Hawthorn Crataegus oliveriana Crataegus orientalis Crataegus pedicellata Crataegus pentagyna Crataegus peregrina Crataegus phaenopyrum - Washington Hawthorn Crataegus pinnatifida - Chinese Hawthorn Crataegus pruinosa - Frosted Hawthorn Crataegus pubescens (syn. C. stipulacea) - Mexican Hawthorn Crataegus punctata - Dotted Hawthorn Crataegus puntamiana Crataegus rhipidophylla (syn. C. rodiformis or C. curvisepala) Crataegus rivularis Crataegus saligna Crataegus sanguinea - Redhaw Hawthorn Crataegus spathulata Crataegus submollis Crataegus succulenta - Fleshy Hawthorn Crataegus tanacetifolia Crataegus triflora Crataegus uniflora Crataegus viridis - Winter King Hawthorn or Green Hawthorn Crataegus wattiana Crataegus wilsonii

Uses

Culinary use

The fruits of the species Crataegus pinnatifida (Chinese Hawthorn) are tart, bright red, and resemble small crabapple fruits. They are used to make many kinds of Chinese snacks, including haw flakes and tanghulu (糖葫芦). The fruits, which are called shānzhā (山楂) in Chinese, are also used to produce jams, jellies, juices, alcoholic beverages, and other drinks [1]. In South Korea, a liquor called sansachun (산사춘) is made from the fruits.[2]

The fruits of Crataegus pubescens are known in Mexico as tejocotes and are eaten raw, cooked, or in jam during the winter months. They are stuffed in the piñatas broken during the traditional pre-Christmas parties known as posadas. They are also cooked with other fruits to prepare a Christmas punch. The mixture of tejocote paste, sugar, and chili powder produces a popular Mexican candy called rielitos, which is manufactured by several brands.

In the southern United States fruits of three native species are collectively known as Mayhaws and are made into jellies which are considered a great delicacy.

The leaves are edible and, if picked in the months of April and May, they are tender enough to be used in salads.

Medicinal use

The dried fruits of Crataegus pinnatifida (called 山楂 or shān zhā in Chinese) are used in naturopathic medicine and traditional Chinese medicine, primarily as a digestive aid. A closely related species, Crataegus cuneata (Japanese Hawthorn, called sanzashi in Japanese) is used in a similar manner. Other species (especially Crataegus laevigata) are used in Western herbal medicine, where the plant is believed to strengthen cardiovascular function [3]. In recent years, this use has been noted and adopted by Chinese herbalists as well [4]. Hawthorn is also used as an aid to lower blood pressure, and treat some heart related diseases.

Clinical trials

Several clinical trials have assessed the ability of hawthorn to help improve exercise tolerance in people with NYHA class II cardiac insufficiency compared to placebo. One trial, at (300mg/day) for 4 to 8 weeks, found not difference from placebo. The second trial, including 78 subjects (600mg/day) for 8 weeks, found "significant improvement in exercise tolerance" and lower blood pressure and heart rate during exercise. The third trial, including 32 subjects (900mg/day) for 8 weeks, found improved exercise tolerance as well as a reduction in the "incidence and severity of symptoms such as dyspnea and fatigue decreased by approximately 50%" .

In the HERB-CHF (Hawthorn Extract Randomized Blinded Chronic HF Study) clinical trial, 120 patients took 450mg of hawthorn extract twice daily for 6 months in combination with standard therapy and a standardized exercise program. "No effects of hawthorn were seen on either quality-of-life endpoint (Tables 1 and 2), or when adjusted for LVEF" .

One study, consisting of 1011 patients taking one tablet (standardized to 84.3mg procyanidin) twice daily for 24 weeks, found "improvements in clinical symptoms (such as fatigue, palpitations, and exercise dyspnea), performance and exercise tolerance test, and ejection fraction" .

Other uses

The wood of some hawthorn species is very hard and resistant to rot. In rural North America it was prized for use as tool handles and fence posts.

Folklore

The custom of employing the flowering branches for decorative purposes on the 1st of May is of very early origin; but since the adoption of the Gregorian calendar in 1752, the tree has rarely been in full bloom in England before the second week of that month. In the Scottish Highlands the flowers may be seen as late as the middle of June. The hawthorn has been regarded as the emblem of hope, and its branches are stated to have been carried by the ancient Greeks in wedding processions, and to have been used by them to deck the altar of Hymenaios. The supposition that the tree was the source of Jesus's crown of thorns gave rise doubtless to the tradition current among the French peasantry that it utters groans and cries on Good Friday, and probably also to the old popular superstition in Great Britain and Ireland that ill-luck attended the uprooting of hawthorns. Branches of Glastonbury Thorn, C. Oxyacantha, var. praecox, which flowers both in December and in spring, were formerly highly valued in England, on account of the legend that the tree was originally the staff of Joseph of Arimathea.

In Celtic lore, the hawthorn plant was used commonly for rune inscriptions along with Yew and Apple. It was once said to heal the broken heart.

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  The fruit of Common Hawthorn (C. monogyna)

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  Spring flowers of the probable hybrid C.laevigata x monogyna

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  Crataegus pinnatifida fruit

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  Botanical drawing of Crataegus laevigata

References and external links

• Photos of Chinese haw berries
• Key to Crataegus of Western North America
• Medicinal uses of Hawthorn in Armenia
• Edible uses of hawthorns at Plants For A Future
• Crataegus phaenopyrum images at bioimages.vanderbilt.edu