american elm

american elm (Ulmus americana)
native
pictures taken in june

the american elm tree is one of several species of elm in the us that was devastated by dutch elm disease brought over in contaminated european logs in the 30s. old elm trees are a bit unusual as a result! dutch elm disease is a fungal problem spread by bark beetles. between 1930 and 1989, over 75% of elm trees in north america had been killed by it. there is actually a vaccine for it now, developed in amsterdam, which protects a tree from the disease for a season. dutch elm disease is still a major problem for elm trees in many locations, and populations of urban elms are typically carefully monitored for signs of it so that they can step in to protect the tree before it's too late.
without the intervention of dutch elm disease, american elms can live for hundreds of years. they enjoy wet areas, like riverbanks and swamps. american elm wood is high in moisture and as a result makes for poor firewood and woodworking material. probably for both of these reasons, it's sometimes called "water elm."
when they're old, american elms are really magnificent; they're massive, and their branches twist and curve in the air. here's a bit of a sad story about an elderly elm that died, with beautiful pictures; here's a tidbit about a still-living (but much younger) elm over in northampton.