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Crataegus
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Hawthorn (Crataegus) is a large genus of shrubs and trees in the rose 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.
They are shrubs and small trees growing to 5-15 m tall, characterized by their small pome fruit and thorny branches.
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Hawthorn (Crataegus) is a large genus of shrubs and trees in the rose 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.
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.
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
Some horticulturally important hybrids
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. The fruits, which are called shanzha in Chinese, are also used to produce jams, jellies, juices, alcoholic beverages, and other drinks . In South Korea, a liquor called sansachun is made from the fruits.To the western palate, drinks made from the fruits taste similar to barbecue sauce.
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. In Canada, where hawthorns are strongly associated with the culture of Manitoulin Island, the fruits are commonly known as hawberries.
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 shan zha 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 . In recent years, this use has been noted and adopted by Chinese herbalists as well . Hawthorn is also used as an aid to lower blood pressure, lower cholesterol, 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 no 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
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