No. Elm trees are not extinct, and USDA Forest Service researchers say elms are not at risk of extinction, even though Dutch elm disease killed most of the large American elms that once lined streets.
Dutch elm disease is a fungus spread by bark beetles. It entered the United States in the 1930s and has since spread through nearly the entire range of the American elm, so most elms have already been exposed. Infected trees wilt and usually die fairly quickly because the fungus blocks their ability to move water. What changed is size, not survival: elms still sprout in forests and yards, but most now die before they grow large. Researchers describe the American elm as having become a “juvenile species” that produces heavy seed crops before it succumbs, so new seedlings keep replacing lost trees. A small number of large survivor elms remain, and the Forest Service and its partners are cloning and testing them to breed disease-resistant trees for replanting, a process that takes about 15 to 20 years.
Source: USDA Forest Service, Forestcast “A Return to Elm Street” transcript
Image: American elm tree in Greenwich, Connecticut, by Marty Aliga, CC BY-SA 4.0, via Wikimedia Commons.