New York Intelligencer [no paywall]: “…In 1904, Herman W. Merkel, a forester at the Bronx Zoo, noticed chestnuts near the park’s perimeter were speckled with a strange orange fungus. Merkel called in William A. Murrill, a mycologist at the New York Botanical Garden, and the two men spent the next year identifying a fungus now known as Cryphonectria parasitica, imported on ornamental Asian chestnut trees. The blight enters via small wounds in the bark made by weather or insects and eats its way through before the trunk erupts open with a warty canker full of “yellowish-brown fruiting pustules,” which release spores to infect nearby trees, wrote Murrill. “No treatment can be suggested except the rigorous use of the pruning knife,” he determined. “The disease seems destined to run its course, as epidemics usually do.” The blight ran through forests like a line of fire, killing close to 4 billion trees by 1940, and it still hasn’t burned out: When the viable chestnut roots below ground send up new shoots, they only live a decade or so before the fungus kills them, too. A small, determined cohort of scientists, growers, and tree lovers refused to accept the end of the chestnut epoch, and in the 1980s, two parallel rescue efforts began…”