White ash

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White ash
White ash

White ash

Systematics
Asterids
Euasterids I
Order : Mint family (Lamiales)
Family : Olive family (Oleaceae)
Genre : Ash trees ( Fraxinus )
Type : White ash
Scientific name
Fraxinus americana
L.
Pinnate leaves

The white ash ( Fraxinus americana ) is a plant from the genus of the ash ( Fraxinus ) in the family of Oleaceae (Oleaceae).

description

The white ash is a tree that reaches heights of up to 26 m (sometimes up to 40 m). The dark gray bark is usually finely cracked and divided into very small short ridges. The treetop is highly arched and open. The branches are thin and straight. The buds are light brown, small and cone-shaped. The heavy and often pendulous leaf is 15 to 30 cm long and pinnate unpaired with seven leaflets. The 1 to 1.5 cm long-stalked pinna leaflets are obovate, tapered long, have a stately length of up to 15 cm and a width of 7 cm. They are dark green above and whitish below. The leaves shoot in Central Europe after the common ash .

The flowers and fruits resemble this one. The white ash is dioeciously gendered ( diocesan ).

The number of chromosomes is 2n = 46.

Occurrence

Distribution of the white ash on the North American continent

The white ash is the most common and most important forest species in North America . Their distribution area is in the eastern half of North America, from northern Florida and East Texas in the south to New Brunswick and Ontario in Canada . The white ash places high demands on the nutrient supply and soil moisture. It grows along streams and on damp ground and tolerates temporary flooding. In youth she is relatively shade-tolerant, but in old age places high demands on the enjoyment of light. It occurs in mixed deciduous forests with sugar maple , tulip tree , American beech , American sweetgum , swamp oak and various hickory nut species . It is a kind of the Liriodendretalia forests and the elm silver maple forests (Ulmo-Aceretalia sacharini). It rises in the north up to altitudes of 600 meters, in the south up to 1500 meters.

The white ash was introduced to Europe in 1724 and grows widely in Central Europe .

Systematics

Fraxinus americana was 1753 Linnaeus in Species Plantarum , 2, p.1057 first published . Synonyms for Fraxinus americana L. are: Fraxinus americana var. Biltmoreana (Beadle) J. Wright ex Fernald , Fraxinus biltmoreana Beadle . Fraxinus americana is part of the section Melioides from the genus of the Fraxinus . According to R. Govaerts, Fraxinus albicans Buckley is also a synonym of Fraxinus americana L. The distribution area then extends to Mexico.

use

The ring-pored wood of the white ash is hard, tough, heavy and very elastic. The sapwood is light whitish, the heartwood brown. It is used similarly to the wood of the common ash .

Pests

The main pest of the white ash is the Asian ash splendor beetle ( Agrilus planipennis , English emerald ash borer ). This insect was first discovered in 2002 as a harmful organism in various ash species on the American continent. It is an invasive species ; the beetle is actually native to Asia and eastern Russia and was probably introduced from there with packaging wood as early as the 1980s or 1990s. So far, ash stocks in Michigan (USA), Ohio (USA) and Ontario (Canada) in particular have been damaged. It is estimated that around 60 million white ash trees have now fallen victim to the beetle, and the insect is considered to be the most destructive insect pest to ever appear in the forests of the United States. The expected economic damage in the decade 2011–2021 is estimated at at least $ 20 billion.

The rust fungus Puccinia sparganioides attacks the white ash.

Individual evidence

  1. ^ Fraxinus americana at Common Trees of the North Carolina Piedmont .
  2. ↑ Fraxinus americana at New Brunswick tree and shrub . ( Memento from March 11, 2008 in the Internet Archive )
  3. ↑ Fraxinus americana at Tropicos.org. In: IPCN Chromosome Reports . Missouri Botanical Garden, St. Louis
  4. ↑ a b Fraxinus americana - entry in GRIN.
  5. ^ Erich Oberdorfer : Plant-sociological excursion flora for Germany and neighboring areas . With the collaboration of Angelika Schwabe and Theo Müller. 8th, heavily revised and expanded edition. Eugen Ulmer, Stuttgart (Hohenheim) 2001, ISBN 3-8001-3131-5 , pp.  748 .
  6. ↑ a b Rafaël Govaerts (Ed.): Fraxinus americana. In: World Checklist of Selected Plant Families (WCSP) - The Board of Trustees of the Royal Botanic Gardens, Kew . Retrieved December 11, 2017.
  7. ^ T. Schröder: The Asian ash splendor beetle. (No longer available online.) Waldwissen.de, 2004, archived from the original on October 15, 2013 ; Retrieved October 14, 2013 .
  8. ^ Biological Control. emeraldashborer.info, accessed October 14, 2013 .
  9. ↑ Ash Rust. University of Delaware. Online Fact Sheet ( Memento from May 7, 2015 in the Internet Archive )

Web links

Commons : White Ash ( Fraxinus americana )  - Album with pictures, videos and audio files