by Andy Newman

NEW YORK - The botanists forged through a thicket and crossed a rocky ravine bed. Their quarry, Polygonatum pubescens, was proving elusive. But they would not rest. They had promised a shipment of its seed to their partners in a bunker across the ocean.

Just beyond a derelict chain-link fence, a man with a beard spotted pea-sized green balls dangling from a miniature awning of shiny oval leaves.

"There's your plant," he called out to another bearded man.

On a wooded Staten Island hillside last Wednesday, a few hundred feet from a busy road, the botanists from the city's native plant center scored another find for a project called the Millennium Seed Bank.

Polygonatum pubescens, slightly better known as hairy Solomon's seal, is hardly the showiest plant in the forest, or the rarest. A plainer cousin to lily of the valley, it makes its home easily in the fragmented woodlands of Staten Island, Queens, the Bronx and similar habitats hereabouts.

Which is why the Millennium Seed Bank Project wants it.

The project, run by the Royal Botanical Garden, at Kew, England, aims to collect seeds from 10 percent of the world's flowering plant species and to stow them in a sort of climate-controlled Noah's Ark against the possibility of depletion, whether by climate change, alien-species invasion, overdevelopment or apocalypse.

The project has received seeds from 100 countries and every imaginable ecosystem, from the palm forests of Madagascar to the tundra of Alaska. In the Western Hemisphere, the project is stockpiling seeds from exactly one urban area: New York City.

This honor is due to the existence of New York's municipal native-plant nursery, which the city says is the only one in the country. The Greenbelt Native Plant Center, a little-known wing of the parks department based in an old farmhouse on Staten Island, has spent two decades raising specimens of the city's indigenous flora - most of them far humbler than hairy Solomon's seal - for use in restoration and replanting projects.

What this means for posterity is that a hundred or a thousand years from now, should the bomb fall or the seas rise, the tellers at the Millennium Seed Bank in West Sussex, England, will be able to open the vault where the seeds are stored at minus 4 degrees Fahrenheit and 15 percent humidity, thaw out some Polygonatum pubescens, and start New York City all over again.

"We New Yorkers sometimes think we're not part of the planet," said Adrian Benepe, the city parks commissioner. "The Millennium Seed Bank is probably the ultimate testimony to the fact that the natural areas of New York City are important, that these plants are worth preserving forever even though to the average New Yorker they may seem like a little inconsequential weed."

The native plant center, with guidance from the Brooklyn Botanic Garden, is giving the Millennium Seed Bank 100 species from within 75 miles of New York City. Since last year, the botanists have collected 24 species, 8 from New York City, including flattened oat grass from the northern reaches of Central Park and northern bayberry from Staten Island.

Today at the botanic garden, officials from the seed bank and from the federal Bureau of Land Management will honor New York's contribution, and may make a brief foray into the garden's Native Flora collection to harvest a few seeds from an allegheny vine.

Until recently, the Greenbelt Native Plant Center, on Victory Boulevard in a western corner of the island, kept its focus local and relatively short term. When the Army Corps of Engineers needs spartina grass for wetlands reclamation or the city needs switchgrass for landfill cover, they call the plant center. But this spring, as thanks for the city's help, the Millennium Seed Bank bought the plant center a climate-control unit so it could start its own long-term seed bank.

Now, next to the greenhouses, a walk-in cooler is filling up with little cotton sacks and plastic bags, each containing thousands of seeds in every possible shape and shade of earth tone - olive-green pellets, reddish-brown shields, fluffy tan podlets with little wings.

There is still plenty of space. "Seed storage doesn't take up a lot of room," said Edward Toth, the plant center's director.

It was last Wednesday that Mr. Toth; Timothy Chambers, the center's nursery manager; and Gerry Moore, the science director at the Brooklyn Botanic Garden, set out on a scouting trip for hairy Solomon's seal. Mr. Chambers has been keeping tabs on several populations this year, hoping that one will be prolific enough to yield the 10,000 seeds that the Millennium Seed Bank demands.

Rattling along in an old green Ford Bronco, the researchers pulled over on Brielle Avenue, opposite a newish string of brass-accented brick houses, and hiked into a tract adjoining a crumbling tuberculosis sanitarium, the old Seaview Hospital. They passed many species they had already collected for the Millennium project - maple-leaved vibernum, steeplebush with spiky stalks of tiny pink flowers, black birch - as well as a particularly impressive specimen of that quintessential Staten Island forest dweller, Automobilius burnedouticus.

The Solomon's-seal colony, growing on a steep, moist bank of the ravine, turned out to be insufficiently fruity. Something - possibly birds, possibly disease - had taken a toll on the green seed balls that hang from the hairy undersides of the leaves.

"We're not going to get 10,000 seeds off this site," Mr. Toth said.

Mr. Chambers was not worried. There were still two weeks before the seeds ripened, and he knew of two other promising colonies in the area.

"It's pretty normal," he said. "Different things come up; populations aren't what I thought."

As a consolation, on the way back to the truck, the researchers paused to take oral samples of the seed covering of Rubus allegheniensis, which they had collected for the Millennium project last summer.

That is, they stopped to eat some blackberries, which were delicious.

Copyright 2007 The New York Times Company