Field elm (Eng); olmo, olmo común, negrillo, álamo negro (Spa); om, olm (Cat); humar hostotxikia (Baq); ulmeiro (Glg); ulmeiro, negrilho (Por).
DID YOU KNOW...? Dutch Elm Disease, an illness affecting elm trees across the globe, is not present in the Canary Islands. For this reason the islands have become an important location for the survival of this and other species.
This deciduous tree can be up to 30 m tall and has a robust form, often with suckers coming out from the base. The trunks of old specimens are usually hollow and the bark is brown and fissured. The leaves are simple, alternate, serrated, up to 8.5 cm long and 6 cm wide. They are oval or lanceolate, with an asymmetrical base and an obvious stalk (5-15 mm) that is not covered by the basal lobe, unlike that of other elm species. They are deep green on the upper side, rough to the touch, and have perfectly traced, parallel veins. As this tree is wind-pollinated, the flowers lack petals and are inconspicuous. This is not true of the fruits, which are dry and appear before the leaves. These seeds are keys, or samaras, that are surrounded by a membranous wing which aids their dispersal by the wind. They are yellow and disc-shaped, with a diffuse, pink-coloured central spot.
This is a species of temperate climes that can live up to altitudes of 1000 m or more and which grows on well-developed, cool, deep soils. In the Canary Islands it is mainly naturalised along the edges of roads and tracks of the high midslopes, or medianías, where, thanks to its basal shoots (suckers), it can form fairly dense copses. It also grows in the monteverde forest formations, where the very moist, fertile soils provide the ideal sustenance.
This tree lives in Europe, Asia, North America and northern Africa. It is very widespread in the Canary Islands as an ornamental and shade tree, but it has only become established in the wild in a very isolated way in the central islands of Tenerife and Gran Canaria.