About Ulmus mexicana (Liebm.) Planch.
Ulmus mexicana (Liebm.) Planch. is one of the tallest elm species, occasionally growing to 84 m (276 ft) in height with a diameter at breast height of 2.5 m (8 ft), making it one of the tallest tree species native to Mexico. This tree is set apart by its deeply fluted grey trunk, which supports a deep crown; its dense foliage casts a heavy shadow. Its leaves vary widely in size, ranging from 3–16 cm long by 2–7 cm broad, and are shaped elliptic to obovate. The upper leaf surface is glossy, while the underside is dull; leaf petioles measure 5–10 mm long. The species has distinctive racemose inflorescences up to 7 cm in length. These inflorescences hold nine clusters of 40 perfect apetalous wind-pollinated flowers, which emerge between December and February. The small samarae measure 9.0 × 2.3 mm, are covered in long straight hairs, and are shed in March. Natural regeneration of Ulmus mexicana is poor. Although most of the tree's natural range is threatened by deforestation, it is not considered endangered, because it is singularly unpopular in the timber trade due to its deeply fluted trunk. Its timber is hard and heavy, with a specific gravity of 0.55, but it is difficult to dry and can warp badly. Additionally, its high silica content (0.35) damages cutting tools. The wood of Ulmus mexicana is used for tools, furniture, and floors, while its foliage is commonly used as cattle fodder. The tree is also occasionally planted for shade or as an ornamental.
