Ulmus pumila var. arborea

Taxobox
status = LC
name = "Ulmus pumila" var. "arborea"


image_caption = var. "arborea", Netherlands. Photo: Ronnie Nijboer, Bonte Hoek kwekerijen
regnum = Plantae
divisio = Magnoliophyta
classis = Magnoliopsida
ordo = Rosales
familia = Ulmaceae
genus = "Ulmus"
species = "U. pumila"
trinomial = "Ulmus pumila" L. var. "arborea"
trinomial_authority = Litv.
synonyms =
*"Ulmus pinnato-ramosa" Dieck
*"Ulmus turkestanica " Regel

"U. pumila" L. var. "arborea" Litv. is endemic to western Siberia and Turkestan. The tree was introduced to Europe by Georg Dieck in 1894 as "U. pinnato-ramosa".

Description

The tree is distinguished from the species by its greater height. The pinnate leaves are 4 - 7 cm in length, ovate-lanceolate, double-toothed and finely pointed. Var. "arborea" grows very vigorously, and can ultimately make a large tree White, J. & More, D. (2003) "Trees of Britain & Northern Europe", Cassell, London. ISBN 0-304-36192-5 ] . The USA national champion tree in Detroit, Michigan, is 45 m tall, with a crown of 34 m width [http://www.northern.edu/natsource/TREESA1/Siberi1.htm] .

Pests and diseases

A specimen at the Ryston Hall [http://www.rystonhall.co.uk/] , Norfolk, UK, arboretum, obtained from the Späth nursery in Berlin before 1914 Ryston Hall Arboretum catalogue, circa 1920] , was killed by the earlier strain of Dutch elm disease prevalent in the 1930s.

Cultivation

The tree is still occasionally found in Europe and North America. Also introduced to Australia, the tree was listed by nurseries there (as "turkestanica") in the early 20th century, but it is not known whether it still survives in that country. There are no known cultivars of this taxon, nor is it known to be available from any nurseries.

Accessions

;North America
*Arnold Arboretum acc. nos. 925-83, 698-87.
*Holden Arboretum acc. no. 60-317
*New York Botanical Garden acc. no. 1032/60 ;Europe
*Hergest Croft Gardens, Kington, Herefordshire, UK. One tree, as "U. pinnato-ramosa"; no accession details available.
*Royal Botanic Garden Edinburgh, acc. nos. 19021007, 20021586
*Sir Harold Hillier Gardens, UK, acc. no. 1977.4795, (as "U. pinnata-ramosa").
*Strona Arboretum [http://arboretum.sggw.pl/wykaz_u.html] , University of Life Sciences, Warsaw, Poland
*University of Copenhagen Botanic Garden, details not available.

References