name = Buckthorn

image_width = 240px
image_caption = Alder Buckthorn ("Rhamnus frangula")
regnum = Plantae
divisio = Magnoliophyta
classis = Magnoliopsida
ordo = Rosales
familia = Rhamnaceae
genus = "Rhamnus"
genus_authority = L.
subdivision_ranks = Species
subdivision = See text.

:"For the genus "Hippophae", see Sea-buckthorn."

The Buckthorns ("Rhamnus") are a genus (or two genera, if "Frangula" is treated as distinct) of about 100 species of shrubs or small trees from 1-10 m tall (rarely to 15 m), in the buckthorn family Rhamnaceae. They are native throughout the temperate and subtropical Northern Hemisphere, and also more locally in the subtropical Southern Hemisphere in parts of Africa and South America.

Both deciduous and evergreen species occur. The leaves are simple, 3-15 cm long, and arranged either alternately or in opposite pairs. One distinctive character of many buckthorns is the way the veination curves upward towards the tip of the leaf. The plant bears fruits which are dark blue berries. The name is due to the woody spine on the end of each twig in many species. Buckthorns are used as food plants by the larvae of some Lepidoptera species – see list of Lepidoptera that feed on buckthorns.


The genus is divided into two subgenera, sometimes treated as separate genera:
*Subgenus "Rhamnus": flowers with four petals, buds with bud scales, leaves opposite or alternate, branches with spines. Species include:
**"Rhamnus alaternus" – Italian Buckthorn
**"Rhamnus alnifolia" – Alderleaf Buckthorn
**"Rhamnus arguta" – Sharp-tooth Buckthorn
**"Rhamnus cathartica" – Common (or Purging) Buckthorn (syn. "R. catharticus")
**"Rhamnus crocea" – Redberry Buckthorn (ssp. "crocea"), Hollyleaf Buckthorn (ssp. "pilosa")
**"Rhamnus davurica" – Dahurian Buckthorn
**"Rhamnus diffusus"
**"Rhamnus globosa" – Lokao Buckthorn
**"Rhamnus ilicifolia" – Hollyleaf Redberry
**"Rhamnus japonica" – Japanese Buckthorn
**"Rhamnus lanceolata" – Lanceleaf Buckthorn
**"Rhamnus libanotica"
**"Rhamnus lycioides"
**"Rhamnus petiolaris"
**"Rhamnus pirifolia" – Island Redberry Buckthorn
**"Rhamnus prinoides" – Shiny-leaf Buckthorn
**"Rhamnus saxatilis" – Rock Buckthorn, Avignon Buckthorn, Avignon Berry (syn. "R. infectoria", "R. infectorius")
**"Rhamnus serrata" – Sawleaf Buckthorn
**"Rhamnus smithii" – Smith's Buckthorn
**"Rhamnus staddo" – Staddo (syn. "R. rhodesicus")
**"Rhamnus tinctoria" - Dyer's Buckthorn (syn. "R. saxatilis" ssp. "tinctorius")
**"Rhamnus utilis" – Chinese Buckthorn

*Subgenus "Frangula": flowers with five petals, buds without bud scales, leaves always alternate, branches without spines. Species include:
**"Rhamnus betulaefolia" ("Frangula betulifolia") – Birchleaf Buckthorn
**"Rhamnus californica" ("Frangula californica") – California Buckthorn, Coffeeberry
**"Rhamnus caroliniana" ("Frangula caroliniana") – Carolina Buckthorn, Indian Cherry (syn. "R. carolinianus")
**"Rhamnus frangula" ("Frangula alnus") – Alder Buckthorn, Glossy or Breaking Buckthorn, Black Dogwood
**"Rhamnus glandulosa" - Sanguinho
**"Rhamnus latifolia" ("Frangula azorica")
**"Rhamnus purshiana" ("Frangula purshiana") – Cascara Buckthorn (syn. "R. purshianus")
**"Rhamnus rubra" ("Frangula rubra") – Red Buckthorn
**"Rhamnus sphaerosperma" ("Frangula sphaerosperma") – West Indian Buckthorn

The Purging Buckthorn or Common Buckthorn ("R. cathartica") is a widespread European native species, in the past used as a purgative, though its toxicity makes this a very risky herbal medicine and it is no longer used. Introduced into the United States as a garden shrub, this has become an invasive species in many areas there. It has recently been discovered to be a primary host of the soybean aphid "Aphis glycines", a problem pest for soybean farmers across the US. The aphids use the buckthorn as a host for the winter and then spread to nearby soybean fields in the spring.

Another European species, Alder Buckthorn ("R. frangula", syn. "Frangula alnus") was of major military importance in the 15th to 19th centuries, as its wood provided the best quality charcoal for gunpowder manufacture.

Italian Buckthorn ("R. alaternus"), an evergreen species from the Mediterranean region, has become a serious weed in some parts of New Zealand—especially on Hauraki Gulf islands.

Dyer's Buckthorn ("R. tinctoria") is used, together with the Asian Chinese Buckthorn ("R. utilis"), to produce the dye "china green". Another species, Avignon Buckthorn ("R. saxatilis") provides the yellow dye Persian berry, made from the berries.

Sanguinho "(R. glandulosa)" is endemic to the Macaronesian islands, where it is found in the "laurisilva" forests of the Madeira and Canary Islands.

North American species include Alder-leaf Buckthorn ("R. alnifolia") right across the continent, Carolina Buckthorn ("R. (F.) caroliniana") in the east, Cascara Buckthorn ("R. (F.) purshiana") in the west, and the evergreen California Buckthorn or Coffeeberry ("R. (F.) californica") and Hollyleaf Buckthorn ("R. crocea") in the west.

In South America, "Rhamnus diffusus" is a small shrub native from the Valdivian temperate rain forests in Chile.

Buckthorns may be confused with Dogwoods, which share the curved leaf venation; indeed, "dogwood" is a local name for "R. prinoides" in southern Africa, a plant used to make Ethiopian mead and known as "gesho" in Ethiopia. The two plants are easy to distinguish by slowly pulling a leaf apart; in dogwood thin white latex strings can be seen, strings not present in buckthorn.

External links

* [http://www.ajol.info/viewarticle.php?id=17292&jid=68&layout=abstract Scientific chemical research on African Rhamnus]
* [http://www.chilebosque.cl/shrb/rdiff.html "Rhamnus diffusus" pictures from "Chilebosque"]
* [http://www.cas.vanderbilt.edu/bioimages/species/frame/frca13.htm "Frangula caroliniana" images at bioimages.vanderbilt.edu]

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Look at other dictionaries:

  • Buckthorn — Buck thorn , n. (Bot.) A genus ({Rhamnus}) of shrubs or trees. The shorter branches of some species terminate in long spines or thorns. See {Rhamnus}. [1913 Webster] {Sea buckthorn}, a plant of the genus {Hippopha[ e]}. [1913 Webster] …   The Collaborative International Dictionary of English

  • buckthorn — [buk′thôrn΄] n. [ BUCK1 + THORN] 1. any of a genus (Rhamnus) of thorny trees or shrubs of the buckthorn family, bearing small greenish flowers and purple berries 2. any of a genus (Bumelia) of trees of the sapodilla family, native to the S U.S.… …   English World dictionary

  • buckthorn — ► NOUN ▪ a thorny shrub or small tree which bears black berries …   English terms dictionary

  • buckthorn — /buk thawrn /, n. 1. any of several, sometimes thorny trees or shrubs belonging to the genus Rhamnus, esp. R. frangula, the bark of which is used in medicine. Cf. buckthorn family. 2. a tree or shrub belonging to the genus Bumelia, of the… …   Universalium

  • buckthorn — dygioji šunobelė statusas T sritis vardynas apibrėžtis Šunobelinių šeimos vaistinis nuodingas (Rhamnus cathartica), paplitęs šiaurės Afrikoje, Europoje ir vakarų Azijoje. atitikmenys: lot. Rhamnus cathartica angl. buckthorn; buckthorn cathartic;… …   Lithuanian dictionary (lietuvių žodynas)

  • buckthorn — noun Any of several, often thorny shrubs or small trees of the genus Rhamnus, especially the common buckthorn or purging buckthorn; Rhamnus cathartica …   Wiktionary

  • buckthorn — šaltekšnis statusas T sritis vardynas apibrėžtis Šunobelinių (Rhamnaceae) šeimos augalų gentis (Frangula). atitikmenys: lot. Frangula angl. alder buckthorn; black alder; buckthorn; dogwood vok. Faulbaum; Pulverholz rus. крушина; крушинник lenk.… …   Dekoratyvinių augalų vardynas

  • buckthorn — noun Date: 1578 1. any of a genus (Rhamnus of the family Rhamnaceae, the buckthorn family) of often thorny trees or shrubs some of which yield purgatives or pigments 2. a shrub or small tree (Bumelia lycioides) of the sapodilla family of the… …   New Collegiate Dictionary

  • buckthorn — SYN: Rhamnus. * * * buck·thorn bək .thȯ(ə)rn n a shrub or tree of the genus Rhamnus sometimes having thorny branches and often containing purgative principles in bark or sap and producing fruits sometimes used as a source of yellow and green… …   Medical dictionary

  • buckthorn — buck•thorn [[t]ˈbʌkˌθɔrn[/t]] n. 1) pln any of several often thorny trees or shrubs of the genus Rhamnus, of the buckthorn family 2) pln a thorny tree, Bumelia lycioides, of the sapodilla family, common in the southern U.S., having large clusters …   From formal English to slang

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