| Ulmus mexicana | |
|---|---|
| Scientific classification | |
| Kingdom: | Plantae |
| Division: | Magnoliophyta |
| Class: | Magnoliopsida |
| Order: | Rosales |
| Family: | Ulmaceae |
| Genus: | Ulmus |
| Species: | U. mexicana |
| Binomial name | |
| Ulmus mexicana (Liebm.) Planch. |
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| Synonyms | |
|
Chaetoptelea mexicana Liebm. |
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The Mexican Elm Ulmus mexicana (Liebm.) Planch. is a large tree endemic to Mexico and Central America. 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. Natural regeneration is poor.
The tree was first described botanically in 1873.[2]
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Ulmus mexicana 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. Apart from its size, the tree is also distinguished by its deeply fluted grey trunk, supporting a deep crown, 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 obovate, 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) comprising nine clusters of 40 perfect apetalous wind-pollinated flowers which emerge between December and February. The small samarae, 9 mm × 2.3 mm, are covered with long straight hairs, and are shed in March [3] [2].
No information available.
The tree is not known to be hardy in Europe; a specimen planted at the Cambridge University Botanic Garden in England in 1978 died for reasons unknown. One tree is known to exist in Australia (see Accessions). There are no known cultivars of this taxon, nor is it known to be in commerce.
The timber is hard and heavy (Gs 0.55), but difficult to dry, and can warp badly; its high silica content (0.35) damaging 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. However, 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]
In Costa Rica the Mexican Elm is known as Tirrá; the neighbourhood (district) of Tirrases in Curridabat, San José, takes its name from the tree.