A good portion of the Garden State's natural heritage is just a chance event or construction project away from being gone forever.

Survival is considered to be in jeopardy for more than 350 of New Jersey's 2,000 or so native flora — plant species that have been on record here for hundreds of years, according to the latest tracking figures from the state Department of Environmental Protection.

Endangered plants are known to exist in five or fewer locations throughout the state.

They're better off right now than the 50 or so native New Jersey plant species that can no longer be found here, but "they're on the brink" of being eliminated — some more than others, said Bob Cartica, administrator for DEP's Office of Natural Lands Management.

"One that's really on the edge of the cliff is a tree called Table Mountain pine," Cartica said. "It only is known from a single location in New Jersey, now or ever. There's only maybe two trees left, and they're not doing so well."

Luckily for scientists, the endangered tree species is located on state property in Hunterdon County. So monitoring the habitat isn't an issue.

"There are 37 other species in New Jersey that are only known from a single location in the state ever," Cartica added.

For many species on the state's endangered list, their presence was never recorded as being much greater. The American lotus, for example, was never known to exist in more than six locations in the state. Today it's down to two.

"A lot of the species that we track were always rare," Cartica said.

Specifically, 820 plant species the DEP tracks are considered "rare." They exist in 50 or fewer locations throughout the state.

According to the state's latest report, habitat loss is widely acknowledged as the leading cause of species extinction and endangerment. New Jersey, it said, has been affected more than other states due to a longer history of development, and a much higher human population density. Climate change and flooding patterns are also listed as factors, among others, that affect plant populations.

Approximately 13 percent of the plant species in the United States can be spotted somewhere in New Jersey, the report said.

Despite tracking that goes back to colonization, experts still come across plant species that can be added to the state's list of native flora. The Fern-leaf Scorpio Flower, for example, was first discovered by a State Park Service employee in 2008 in Whittingham Wildlife Management Area. On the state's endangered list, it's known to only exist in one spot, as well as Virginia.

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