'Tis the season for roasting chestnuts. But in the US, native ones are almost gone

abcnews.go.com:

Right now chestnut enthusiasts are cozying up next to their open fires (or toaster ovens) to roast a holiday snack that has long roots in North America

It's been a very long time since vendors sold the American chestnut on city sidewalks. It's no longer the variety whose smell some people associate with Christmastime as it wafts from street carts. Because it's virtually extinct.

But memories of the American chestnut's legacy keep resurfacing for the researchers who want to bring it back. They describe its wood that paneled the homes and schoolrooms of their grandparents, or the photographs of men on the street corners of old Baltimore, with hot bags of nuts cooked on charcoal.

“You can feel that connection to a place, and that connection to utility, and the connection to the importance that this tree played in virtually every aspect of the lives of people,” said Sara Fern Fitzsimmons, chief conservation officer with The American Chestnut Foundation, which is working to restore the tree to flourish as it once did.

Fitzsimmons said that will likely take a lot longer than many chestnut enthusiasts had hoped. Researchers have hit roadblocks with attempts to breed or genetically modify a version that can withstand the invasive blight that has hammered the species since the early 1900s. If and when they do find the right variety, they'll need to figure out how to plant it and help it thrive in forests that are under pressure from climate change, globalization and development.

Once a hallmark of forests from Georgia to New England, American chestnuts now exist mostly as a vast network of root systems underground, sending up shoots. They grow for a time, but the fungal blight takes hold when the trees start maturing. East Asian