ODESSA, March 22 — The seeded Florida grapefruit, long a staple of the American breakfast, has all but died at the age of 187 after an extended illness. The cause was inconvenience.

As its devoted fans can attest, the classic white, seed-studded Duncan grapefruit, named for the grower who introduced it commercially in 1892, has become virtually impossible to find, completing one of the greatest disappearing acts in all of American agriculture. Survivors include the Marsh, ruby red, star and other comparatively flavourless descendants piled high in supermarkets everywhere.

But the Duncan’s death could prove short-lived. As I learned in my own quest for the fruit, there are signs of resurrection as it makes an arduous transition from near extinction to reincarnation, as an heirloom. One of the last Florida groves to sell Duncans until its old trees died a few years ago, CeeBee’s Citrus in Odessa, 25 miles north of Tampa, recently planted 53 new ones, the largest such initiative in decades.

Though still less than 3 feet (91cm) tall, those fledglings are good news for people like Raymond Hunter, 81, a retired theoretical nuclear physicist from Royston, Georgia. Every February for 15 years, he had come to CeeBee’s and stuffed 12 bushels of Duncans — the maximum allowable under Florida fruit inspection laws — into his Lincoln Town Car.

"It’s a strictly hedonistic thing,” he said. "I can surround myself with half a dozen of them cut in half and a grapefruit spoon and saltshaker and have an orgy.”

Once trees bearing Duncans blanketed Florida: either enormous, stately things grown from seeds, or from branches grafted onto existing citrus trees. Yes, the seeds, clustered at the fruit’s core, were irritating, but nearly everyone in the industry acknowledged the Duncan’s superiority.

"The finest, sweetest grapefruit in the world,” said Jim Ellis, 82, a longtime grower and packer in Bartow and, as of March 10, the newest inductee into the Florida Citrus Hall of Fame.

In most realms of life, seediness isn’t a fatal flaw. But with oranges and grapefruit, it has proved nearly as perilous as diseases, freezes and hurricanes. What nature had given the Duncan to perpetuate itself — as many as 60 seeds apiece — had backfired.

Duncans accounted for barely 1 per cent of Florida’s grapefruit acreage last year, said Candi Erick of the State Agricultural Statistics Service, and even that sounds inflated. In his two decades in the business, Dave Nicely of Sun Harvest Citrus in Fort Myers said, he had never eaten one. Marty McKenna, a longtime grower in Lake Wales, can’t point you to a single tree.

Scattered survivors pop up in backyards, and specimens reside at the Citrus Research and Education Center in Lake Alfred and the State Bureau of Citrus Budwood Registration in Chiefland. But no Duncans sprout among the 1 million citrus seedlings in Phil Rucks’ nursery in Frostproof, whose focus is on cultivating new, bug-resistant varieties rather than on salvaging historic ones.

Citrus came to Florida with the conquistadors. But only in 1830 did Odet Phillippe — who claimed, probably spuriously, to have been Napoleon’s surgeon — bring grapefruit from Barbados or Jamaica or Cuba to Safety Harbor, near Tampa. Sixty years later, a onetime insurance man named AL Duncan grafted buds from Phillippe’s original planting to the branches of sour orange trees in Dunedin, 7 miles away, and the Duncan grapefruit was born.

"I do not know how either tree or fruit could be improved,” Duncan said.

Duncan grapefruits at Hollieanna Groves in Maitland, Florida February 28, 2017.

Little more is known about Duncan himself, who vanished back into the insurance trade; he has even been snubbed by the Citrus Hall of Fame in Lakeland, where 187 others, Anita Bryant among them, have been enshrined. But pioneering Florida nurserymen preferred his "grape fruit” to more convenient varieties, and understandably: Bracing and complex, simultaneously sweet and tart, they taste — at least to anyone with a memory — like grapefruit.

But impatient consumers have spurned them for more muted, muddy and colourful alternatives, preferring anything pink or, better yet, red, to the white Duncan.

It’s tempting to blame 21st-century laziness for the Duncan’s travails, but they date back at least to 1930. Even the Greatest Generation succumbed: In 1945, the Florida Citrus Commission noted the public’s growing preference for seedlessness.

The Duncan had its victories; in the 1950s, Harry & David regularly named it "Fruit of the Month.” The Florida Citrus Commission tried turning vulnerability into a virtue. "Duncan grapefruit... with extra seeds... give extra vitamin C... and extra flavour!” it proclaimed in a 1961 newspaper ad.

That didn’t work, nor did claims that the seeds were, as the head of the Florida Citrus Growers Association maintained in 1957, a "tonic for manliness.” Duncans were exiled to Japan, or sectioned and sold in jars, or made into juice.

Seeds weren’t the only problem. Repeated freezes significantly reduced all citrus groves, as did suburbanisation, and Disney World. High labour costs made segmenting them too expensive. People stopped making, and climbing, the distinctive wooden ladders tall enough to scale Duncan trees.

Because Duncans are slower to mature (and sweeten), their season is shorter. And like other seeded citrus, they bear substantially only every other year. The year-round supply of fruit that has come with globalisation helped kill holiday fruit baskets, and everyone to whom they were once sent moved to Florida anyway, or so it seemed.

For single and working parents, it was time-consuming enough to pour juice from a carton, let alone to manicure grapefruit with those old-fashioned serrated spoons. Power drinks and Frappuccinos pushed aside fruit juice. People taking some antidepressants and (especially damaging, given grapefruit’s geriatric constituency) cholesterol drugs were warned to lay off. And by inveighing against sugar, even fructose, Dr Mehmet Oz and Michelle Obama only made things worse for grapefruit growers. The grapefruit-based cocktails swilled on Sex and the City provided only temporary relief.

I had long procured my Duncans from the Citrus Place in Terra Ceia, near Sarasota. That its owner, Ben Tillett, 85, had them at all was a fluke. His father had planted Duncans in 1950, but scared, even then, about relying on seeded fruit, he had replaced them almost immediately with ruby reds. But the handful of shoots he failed to pull produced a few bushels of Duncans a year. Demand shot up whenever Jeff Klinkenberg, a longtime Duncan devotee and veteran chronicler of Florida culture for The Tampa Bay Times, wrote that Tillett still had a few.

By last year Tillett’s trees, too, had died, yet more casualties of the Asian citrus psyllid responsible for the greening disease that has devastated Florida’s citrus groves. And the small number of Duncan trees that his son, Sid, planted will take another year or two to produce anything appreciable.

Taking no chances this year, I broadened my search to county agricultural agents, agronomists, industry journalists and, most crucially, Brenda Eubanks Burnette of the Citrus Hall of Fame, who put out an all-points bulletin for me. Enter Jason Lingle of Hollieanna Groves in Maitland, Florida, near Orlando. Lingle no longer has Duncan trees of his own, either, but he tends to a small number, perhaps 100 years old, on a gated estate nearby.

Jason Lingle with a Duncan grapefruit tree near Hollieanna Groves in Maitland, Florida February 28, 2017.

Though still gamely bearing fruit, the first couple we saw were clearly on their way out. But a pair at the rear of the property were defiantly alive and gloriously fecund.

Perched precariously atop his ladder loading Duncans into the traditional harvesting bag slung over his shoulder, Lingle very nearly tipped over from the weight. He had soon picked more than 3 bushels, which he poured into old-fashioned wooden field boxes.

One of them I intercepted. It should have been the best grapefruit I’d ever eaten: a Duncan freshly picked from an old tree (which produces the sweetest fruit), free of insecticides (its skin mottled by a mite that old-timers say makes it sweeter still) and perched beneath live oaks that had enriched the sandy Florida soil. And so it was.

CeeBee’s longtime owner, William Burchenal, also loved his daily Duncan, and shortly before he turned 88 last summer, he installed two long rows of baby trees where the old ones, from which they had been grafted, once stood.

Burchenal didn’t see them bear fruit; he died in December. His grandson, Adam Burchenal, who now runs the business, anticipates demand for Duncans not just from old customers, but also from elite purveyors up north to whom he already sells other exotic citrus. "It’s just a matter of educating people,” he said.

Adam Burchenal considered taking the first — and, up to now, the only — Duncan the new trees had yielded, to his grandfather’s funeral, but it was still too green. Then someone absconded with it.

As soon as another ripens, he plans to pick it, and to squeeze some of its juice on his grandfather’s grave. — The New York Times