Ulmus mexicana

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Ulmus mexicana

Kingdom:	Plantae
Division:	Magnoliophyta
Class:	Magnoliopsida
Order:	Rosales
Family:	Ulmaceae
Genus:	Ulmus
Species:	U. mexicana

Binomial name

Ulmus mexicana
(Liebm.) Planch.

Synonyms

Chaetoptelea mexicana Liebm.

The Mexican Elm Ulmus mexicana (Liebm.) Planch. is probably the tallest of all the elm species, occasionally reaching a height of 84 m (273 feet), and a d.b.h. of 2.5 m (8 feet), certainly one of the tallest trees in Mexico. It is most commonly found in cloud forest and the higher elevations (800 m to 2200 m) of tropical rain forest with precipitation levels of between 2 m and 4 m per annum ^[1], ranging from San Luis Potosi south to Chiapas in Mexico, and from Guatemala to Panama beyond. Apart from its size, the tree is also distinguished by deep, longitudinal channels along its grey trunk. The crown is deep, its dense foliage casting a heavy shadow. The leaves vary widely in size from 3 - 16 cm in length by 2 - 7 cm breadth, elliptic to ovate, surface glossy, but dull on the underside, with petioles 5 - 10 mm long. The tree is also distinguished by its long, racemose inflorescences (< 7 cm) holding nine inflorescences, each bearing 40 flowers, which emerge between December and February. The small (9 mm x 2.3 mm) samarae, which are covered with long straight hairs, are shed in March ^[2]. Natural regeneration is poor.

The tr4ee is not known to be in cultivation in Europe. A specimen planted at the Cambridge University Botanic Garden in England in 1978 died for reasons unknown. There are no known cultivars of this taxon, nor is it known to be available from any nurseries.

1 Uses
2 Arboreta etc. accessions
3 References
4 External links

[edit] Uses

The timber is hard and heavy (Gs 0.55), but difficult to dry, and can warp badly; its high silica content (0.35) damages tools. The wood is used for tools, furniture, and floors, whilst the foliage is commonly used as fodder for cattle. The tree is occasionally planted for shade or ornamentation. Howvever, although much of its natural range is threatened by deforestation, the tree is singularly unpopular in the timber trade on account of its deeply fluted trunk, and thus not considered a threatened species ^[1].

[edit] Arboreta etc. accessions

North America

Jardin Botanico Francisco Javier Clavijero [2], Xalapa, Veracruz, Mexico. Details not known.

Australasia

Royal Botanic Garden Sydney, Sydney, Australia, acc. no. 851550

[edit] References

^ ^a ^b Moreira, I. & Arnaez, E. (2003) Ulmus mexicana (Liebm.) Planch., Tropical Tree Seed Manual, p. 770-771, RNGR, USDA Forest Service, USA. [1]
^ Todzia, C. A. & Panero, J. L. (2006). A new species of Ulmus (Ulmaceae) from southern Mexico and a synopsis of the species in Mexico. Brittonia, Vol 50, (3): 346