Dogwood

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Dogwood
Cornelian cherry (Cornus mas), illustration

Cornelian cherry ( Cornus mas ), illustration

Systematics
Eudicotyledons
Nuclear eudicotyledons
Asterids
Order : Dogwood-like (Cornales)
Family : Dogwood family (Cornaceae)
Genre : Dogwood
Scientific name
Cornus
L.

Dogwood ( Cornus ), also called horn shrub, is a genus of plants within the dogwood family (Cornaceae). The 55 or so species are mostly found in the temperate areas of the northern hemisphere , some also in the subtropics .

Description and ecology

The dogwood species are mainly shrubs and small trees , more rarely perennial herbaceous plants . Only a few species are evergreen. The mostly oppositely arranged leaves are mainly divided into a petiole and a leaf blade. The simple leaf blades are entire. The leaf veins are characteristically curved towards the tip of the leaf. Stipules are absent.

At the ends of the branches there are usually many flowers together in panicle , dold -like or head-shaped inflorescences . With the exception of the African species Cornus volkensii , all dogwoods have hermaphroditic flowers. The flowers are four-fold. The four sepals are connected together and the under constant ovary grown. The four free petals are usually white, less often yellow, only dark purple in the Swedish dogwood ( Cornus suecica ). There are four stamens , between the stamens and the ovary is a nectar- secreting disc . The gynoeceum consists of two (rarely more) carpels , the single stylus ends in a mostly undivided scar .

There are drupes formed, corresponding to the two carpels there are two ovules, of which but often only one is designed for embryo. In some species the fruits of an inflorescence are fused to form a fruit cluster. The seeds are dispersed by birds, and the development of larger fruit clusters may be related to monkey dispersal.

distribution

The genus Cornus is common in the entire northern hemisphere . Most Cornus species are found in East Asia, but there is also a large variety in eastern North America. Few species occur in Central America, one species still in South America and another in tropical East Africa.

In Central Europe , the two species Cornus and dogwood widespread in northern Germany rarely finds the Swedish dogwood . Numerous species from Asia and North America are used as ornamental trees. The white dogwood , for example, is naturalized in parts of Central Europe.

Closely related species or groups of species within the genus Cornus are sometimes found on different continents, so they are disjointly distributed.

Subgenus Arctocrania : fruits of the Canadian dogwood ( Cornus canadensis )
Subgenus Arctocrania : Swedish dogwood ( Cornus suecica )
Subgenus Cornus : inflorescences and last year's fruits of the Asiatic cornel ( Cornus officinalis )
Subgenus Cynoxylon : flower dogwood ( Cornus florida )
Subgenus Kraniopsis : Tatar dogwood ( Cornus alba )
Subgenus Mesomora : Branch with foliage leaves and inflorescences of Wechselblättrigen dogwood ( Cornus alternifolia )
Subgenus Syncarpea : inflorescence of the Asian dogwood ( Cornus kousa )

Systematics

The genus Cornus was established by Carl von Linné . Synonyms for Cornus L. are: Afrocrania (Harms) Hutch. , Arctocrania Nakai , Benthamia Lindl. nom. illeg., Benthamidia Spach , Bothrocaryum (Koehne) Pojark. , Chamaepericlymenum Hill , Chamaepericlimenum Hill orth. Var., Cornella Rydb. , Cynoxylon Raf. , Dendrobenthamia Hutch. , Discocrania (Harms) M.Král , Eukrania Raf. , Macrocarpium Nakai , Ossea Lonitzer ex Nieuwl. & Lunell nom. superfl., Swida Opiz , Telukrama Raf. , Thelycrania (Dumort.) Fourr. , Yinquania Z.Y.Zhu .

The genus Cornus has already been divided into several genera by various authors. The genus seems to have split into a branch with red and one with white or dark blue fruits quite early on. The types can be divided into the following groups:

Types (selection)

  • Perennial dogwood (Subgenus Arctocrania (Endl.) Rchb. ): It has conspicuous bracts and red fruits. It contains about three types:
  • Cornelian cherries (Subgenus Cornus , Subgenus Sinocornus Q.Y.Xiang and Subgenus Afrocrania (Harms) Wangerin ): It has inflorescences without conspicuous bracts, yellow petals and red fruits. It contains four to six types:
  • American dogwoods (subgenus Cynoxylon (Raf.) Raf. And subgenus Discocrania (Harms) Wangerin ): It has flower heads with striking bracts and red fruits:
  • Dogwood (Subgenus Kraniopsis Raf. ): It has open flower umbels and white or dark blue, round fruits. It contains about 30 species:
  • Tatar dogwood ( Cornus alba L. ): It is widespread from Northeastern Europe to Korea.
  • Silky-haired dogwood ( Cornus amomum Mill. ): It is common in the USA with two subspecies.
  • Cornus austrosinensis W.P. Fang & WKHu : It occurs in Guangdong, Guangxi, Guizhou and Hunan.
  • Cornus bretschneideri L.Henry : It occurs in Gansu, Hebei, Heilongjiang, Henan, Hubei, Jilin, Liaoning, Nei Mongol, Ningxia, Qinghai, Shaanxi, Shanxi and Sichuan.
  • Cornus coreana Wangerin : It occurs in Korea and Liaoning.
  • Cornus drummondii C.A.Mey. : It is common from southeast Michigan to Texas.
  • Cornus hemsleyi C.K. Schneid. & Wangerin : It occurs in Gansu, Guizhou, Hebei, Henan, Hubei, Qinghai, Shaanxi, Shanxi, Sichuan, Xizang and Yunnan at altitudes between 1000 and 4000 meters.
  • Cornus koehneana Wangerin : It occurs in Gansu, Shaanxi, Shanxi and Sichuan at altitudes between 1700 and 2200 meters.
  • Cornus macrophylla Wall. : It occurs in Afghanistan, Bhutan, India, Kashmir, Myanmar, Nepal, Pakistan and in China.
  • Cornus oligophlebia Merr. : It occurs in Bhutan, India, Myanmar, Thailand, Vietnam and in southeastern Yunnan.
  • Cornus papillosa W.P. Fang & WKHu : It occurs in Sichuan and Yunnan.
  • Cornus parviflora S.S.Chien : It occurs in Guangxi and Guizhou.
  • Cornus quinquenervis Franch. : It occurs in Fujian, Gansu, Guangdong, Guangxi, Guizhou, Hubei, Hunan, Jiangsu, Shaanxi, Sichuan and Yunnan.
  • Cornus racemosa Lam. : It is common in the eastern USA to Texas.
  • Red dogwood ( Cornus sanguinea L. ): The four or so subspecies are distributed from Europe to Lebanon.
  • Cornus schindleri Wangerin : It occurs in Gansu, Guizhou, Henan, Hubei, Shaanxi, Sichuan, Xizang and Yunnan at altitudes between 1100 and 3200 meters.
  • Silky dogwood ( Cornus sericea L. ): It is widespread from Alaska to the United States.
  • Cornus ulotricha C.K. Schneid . & Wangerin : It occurs in Gansu, Guizhou, Henan, Hubei, Shaanxi, Sichuan, Xizang and Yunnan at altitudes between 800 and 2700 meters.
  • Cornus walteri Wangerin : It occurs in China at altitudes between 300 and 3000 meters.
  • Cornus wilsoniana Wangerin : It occurs in Fujian, Gansu, Guangdong, Guangxi, Guizhou, Henan, Hubei, Hunan, Jiangxi, Shaanxi, Sichuan and Zhejiang.
  • Pagoda dogwood (Subgenus Mesomora Raf. ): It has open flower umbels and dark blue, round fruits. It contains only two types:
  • Alternate-leaved dogwood ( Cornus alternifolia L. f. ): It is distributed from central and eastern Canada to the north-central and eastern United States.
  • Pagoda dogwood ( Cornus controversa Hemsl. ): It is distributed from the central Himalayas to the southern Kuril Islands .
  • Asian dogwood (subgenus Syncarpea (Nakai) QYXiang ): It has conspicuous bracts and all the fruits of a flower head are fused. It contains about five types:
  • Subgenus Yinquania (ZYZhu) QYXiang & Boufford : It has oval, dark blue fruits. It contains one or two types:
  • Cornus oblonga Wall. : This evergreen little tree is widespread from Pakistan to south-central China.
  • Cornus peruviana J.F. Macbr. : It is common from Costa Rica to northwestern Venezuela and Bolivia.

literature

Individual evidence

  1. ^ Richard H. Eyde: The Case for Monkey-Mediated Evolution in Big-Bracted Dogwoods. In: Arnoldia. , Volume 45, Issue 4, 1985, pp. 3-8. ISSN  0004-2633 (PDF file; 516 kB)
  2. ↑ a b c d e f g h i j k l m n o Rafaël Govaerts (Ed.): Cornus. In: World Checklist of Selected Plant Families (WCSP) - The Board of Trustees of the Royal Botanic Gardens, Kew . Retrieved October 25, 2018.
  3. ↑ a b c d e f g h i j k l m n o p q r s t u v w x Qiu-Yun Xiang, David E. Boufford: Cornaceae. : Cornus , p. 206 - the same text online as the printed work , In: Wu Zheng-yi, Peter H. Raven, Deyuan Hong (Ed.): Flora of China. Volume 14: Apiaceae through Ericaceae , Science Press and Missouri Botanical Garden Press, Beijing and St. Louis, 2005. ISBN 1-930723-41-5

Web links

Commons : Dogwood ( Cornus )  - album with pictures, videos and audio files
Wiktionary: dogwood  - explanations of meanings, word origins, synonyms, translations