WORCESTER — Picking the ripe fruit of a bushy, 10-foot high tree might seem uneventful in this fall season.

But when that fruit is not an apple but nuts from a tree that was effectively wiped out by disease, it becomes something exciting.

“This is the first time that chestnuts have been produced in Worcester since the blight 100 years ago,” said Lois Melican of Spencer, president of the Massachusetts and Rhode Island chapter of The American Chestnut Foundation.

“This is a momentous event for us,” added her husband, Denis Melican.

The American chestnut, Castanea dentata, was once the keystone species in the Eastern forest, representing at least one out of every four hardwoods. Considered the “redwood of the East” for its formidable size — as tall as a 12-story building and with notable girth, Mr. Melican said — the American chestnut was an important food source. A mature tree produced up to 15 bushels of nuts that provided fall forage for animals wild and domestic.

“All animals love chestnuts,” said Mrs. Melican.

Including the human ones.

Mrs. Melican described the American chestnut as providing America’s “first fast food,” with roasted nuts appearing on street corners and in a classic Christmas song by Nat King Cole.

Meanwhile, the straight-grained, fast-growing wood was naturally rot-resistant — a precursor to pressure-treated wood — and was used for railroad ties, utility poles, furniture, and to frame buildings.

“Many of the barns built in the 1880s in Worcester have a chestnut framing,” Mrs. Melican said.

But in 1904, a fungal disease called chestnut blight was introduced to America on imported Asiatic chestnut trees. The blight spread across the East, hitting Massachusetts in 1912-1915, Mrs. Melican said, destroying 4 billion trees by 1950.

The destruction has been called the greatest ecological disaster in the history of the world’s forests.

But the tree is only considered “functionally extinct,” by the United States Department of Agriculture, because the blight does not kill the tree’s root system. This enables it to send up shoots that can reach 20 feet high before they succumb to the disease.

And the tree has some important allies, including The American Chestnut Foundation, which has been cross-breeding American chestnuts with Chinese chestnuts since 1983 to develop a blight-resistant tree with the characteristic height and form of the American chestnut.

On Arbor Day 2014, the foundation teamed up with the Worcester Tree Initiative to plant blight-resistant American chestnuts in Green Hill Park.

“These are the most blight-resistant chestnuts we have so far,” Mrs. Melican said, explaining that the trees were members of the sixth generation of cross-bred trees and were 15/16ths American chestnut.

This spring, one of the five remaining trees flowered for the first time, enabling Mrs. Melican to fertilize it with blight-resistant pollen.

The Melicans, and Derek Lirange and Ruth Seward of the tree initiative returned Thursday to harvest — quite literally — the fruits of that labor: eight burrs that contain two to three chestnuts inside.

“These will be generation seven,” Mrs. Melican said, proud as any parent.

The nuts will be overwintered in a refrigerator to mimic the winter cold, then potted in the spring. After a year in a greenhouse, the seedlings will be ready to be planted.

“There’s so many pests and so many blights that attack our trees, it’s great to see a tree come back that was so important to Worcester and to New England,” said Ms. Seward, executive director of the Worcester Tree Initiative. She said that someday she hoped to see a blight-resistant chestnut grove at the park.

“The story is about hope,” Mr. Melican said, holding a bag with the burrs and chestnuts.

“That you can recover from a devastating blight and have hope ... everybody likes that.”