Elm

Elms are  deciduous and semi-deciduous trees,making up the genus Ulmus, family Ulmaceae found throughout the Northern Hemisphere from Siberia to Indonesia, Mexico to Japan. They have alternate, simple, single- or doubly-serrate leaves, usually asymmetric at the base and sharply pointed at the tip.

Elms are hermaphroditic, having perfect flowers, and which, being wind-pollinated, are without petals. The fruit is a round samara.

Elms take many decades to grow to maturity.

References

Collin, E. (2001). Elm. In Teissier du Cros (Ed.) (2001) Forest Genetic Resources Management and Conservation. France as a case study. Ministry of Agriculture and Fisheries, Bureau of Genetic Resources. INRA DIC. France.
Cornell University: Elm hybrids (pdf file)
Martín-Benito D., Concepción García-Vallejo M., Alberto Pajares J., López D. 2005. Triterpenes in elms in Spain. Can. J. For. Res. 35: 199–205 (2005).  
Mittempergher, L. & Santini, A. (2004) The history of elm breeding. Investigacion agraria: Sistemas y recursos forestales 13(1): 161-177 (2004).
Ware, G. (1995). Little-known elms from China: landscape tree possibilities. Journal of Arboriculture, (Nov. 1995). International Society of Arboriculture, Champaign, Illinois, USA.  .

Other websites
Northern Arizona University: Elm trials.

Category:Trees
Category:Ulmaceae