Four thousand feet above sea level in Hawaii’s Kokeʻe State Park, the weather is drier and cooler than the island of Kauaʻi below. Unlike the lowland, where invasive species dominate the landscape, there’s a forest of mostly native trees and plants all around us. “It’s very pleasant to walk in,” says Steve Perlman. A field botanist who’s been at the forefront of protecting Hawaii’s endangered plants for over 40 years, he’s known for rappelling from ridges to find rare plants. In 2014, he joined the Plant Extinction Prevention Program (PEPP), which focuses on protecting Hawaiian plants that only have fewer than 50 individuals left in the wild.

We arrive at a spot where the trail enlarges a bit and is covered in gravel. The gravel was put there after the trail flooded and hikers began piercing another trail through the forest, unknowingly walking over rare and precious native plants. Perlman points one out — it’s small and frail, with a beautiful, elongated white flower and over 10 buds. It’s called Psychotria grandiflora, or Kopiko, and there are only 30 or so plants left on Kauaʻi, the only Hawaiian island where it grows.

Kopiko is in danger for a variety of reasons — it has to compete with voracious weeds that are not native to Hawaii, as well as deal with non-native pigs, goats, and deer that love munching on its leaves, and rats eating its seeds. Most of the plants that are left are also female, Perlman says, so it’s hard for them to get pollinated by rare male plants. If they’re not pollinated, they can’t make fruits and seeds to reproduce themselves. This is where Perlman and PEPP come in.

With help from a botanist in Japan, Perlman and his colleagues have been hand-pollinating the remaining Psychotria grandiflora by collecting viable pollen from male plants and dabbing it onto the female flowers, allowing them to reproduce. This plant, with the beautiful white flower we’re looking at along the trail, is a natural offspring of that artificial pollination. And it’s safe to say that, if it weren’t for PEPP, this plant species maybe would have been extinct in the wild by now.

Psychotria grandiflora is just one example. There are currently 238 plant species that PEPP is trying to save from extinction. But the future of PEPP itself is in peril. Since its beginning in the early 2000s, the program has been funded by mostly federal money; the budget varied year to year, but it was about $1 million, says Joan Yoshioka, Hawaii’s statewide PEPP manager. The bulk of that money — about 70 to 90 percent — came from the US Fish and Wildlife Service, she says, as well as other federal grants.

In the last year alone, however, the FWS funding has been cut by 50 percent, to about $500,000. And come October, when the new fiscal year begins, Yoshioka is expecting more cuts — possibly another 50 percent. (Including all sources of revenue, PEPP raised only 75 percent of its budget, Yoshioka says.) Perlman’s helicopter budget — around $50,000 — has already been slashed, he says. He desperately needs that money to access rare species that only grow on steep cliffs where no cars can get to. Without the federal money, saving endangered species will be a real challenge. “It may mean we might lose species,” Yoshioka says. “That’s just the reality of it.”

The cuts aren’t only coming from the Fish and Wildlife Service, either. PEPP has seen its budget from the state of Hawaii decrease as well, Yoshioka says. And private grants are becoming harder to get. “We’ve received cuts across the board,” she says.

Extinction prevention programs like PEPP are key for protecting our endangered species — and Hawaii needs it more than any other US state. Hawaii is an island ecosystem, which means that its unique plants evolved isolated from the rest of the world for millions of years. They’re incredibly vulnerable because they don’t have the defense mechanisms to ward off invasive weeds and animals that were introduced on the islands by people. Several types of mint found in Hawaii, for example, don’t have the distinctive mint taste that the plant has in the continental US, because they didn’t evolve having to defend themselves from grazing animals that are usually repelled by that mint taste.

Since Hawaii was inhabited, first by the Polynesians and then by Europeans, the islands have lost over 130 plant species, Yoshioka says. Today, the state — which is dubbed “the endangered species capital of the world” — is home to more than 40 percent of all endangered and threatened plant species in the United States. Before PEPP was created, one plant species a year went extinct on average. But since then, the program has been able to save all of the plants it’s been working on, Yoshioka says. Some of them barely exist in the wild anymore, but they live in enclosed areas where voracious pigs and deer are fenced out, or they live on in nurseries around the world.

“One of the core values of the PEP program in particular is that it’s been very successful,” says Loyal Mehrhoff, the endangered species recovery director at the Center for Biological Diversity, who worked as a field supervisor at the Fish and Wildlife Service’s Pacific Islands Office in Hawaii. During his years at the FWS, Mehrhoff helped create and then fund PEPP.

Take Brighamia insignis, a critically endangered plant that has the unusual shape of a miniature palm tree with cabbage-like leaves at the top and yellow flowers. This plant can only be found in Hawaii, and, in fact, there’s only one plant left in the wild on the island of Kauaʻi, Perlman says. The problem is that goats love their leaves, rats eat their seeds, invasive weeds overgrow them, and they’re pollinated by a very rare, large native moth called the fabulous green sphinx moth. When Perlman began working as a botanist in the mid-1970s, there were probably around 150 Brighamia insignis plants, he says. He began collecting the seeds and growing them at the National Tropical Botanical Garden in Kauaʻi, as well as sending seeds to dozens of botanical gardens around the world. Today, more than 100,000 Brighamia insignis plants are grown in cultivation all over the world, he says, including in Belgium, where people love them as houseplants.

Perlman and Yoshioka recognize that it’s easy to see the work that PEPP does as a lost cause — a bunch of Don Quixotes tilting at windmills. Even for “success stories” like that of the Brighamia insignis, the plants are basically extinct in the wild. “You could be overwhelmed and just go, ‘What’s the use? Either a rat or disease or something is gonna get it, there’s just no point,’” Perlman says. “But for those of us who love these species and really are trying, you just do the best you can.” Hawaii’s plants are more resilient than people think, he says. Most of these plants arrived in these islands in the middle of the Pacific in one seed only, brought by the wind. They were selected to survive even when they’re in extremely low numbers. So even when there’s just a couple of plants left in the wild, there’s hope they will rebound.

“I don’t think any of them are lost causes,” Yoshioka says. “You can go from one plant to a self-sustaining population. We’ve seen that time and time again.”

But without PEPP’s work, these plants honestly don’t have much of a chance. We can’t eradicate rats, weeds, or the feral pigs and goats that are destroying the native flora. We can’t bring the islands back to what they were before humans arrived. So these plants need our help to survive. “We’ve seen it all over the world: we irreversibly transformed landscapes,” Yoshioka says. “I think it’s the responsibility we each feel for preserving what remains, not only for us but future generations. It’d be horrendous if it was lost in a very short time frame.”

The challenge will be to continue the work with the ongoing budget cuts. The PEPP staff is already down to 11 people, and Yoshioka expects there may be layoffs. The funding situation at the federal level isn’t expected to get any better, either. Though the cuts began during the previous administration, President Donald Trump is requesting a 12 percent cut to the Interior Department, which oversees the Fish and Wildlife Service. Trump has also made it pretty clear in his first few months in office that he’s dismissive of conservation and climate change. “Our federal funding levels are decreasing and so our ability to continue to provide financial support to our partners is shrinking as federal budgets shrink,” says Miel Corbett, the Fish and Wildlife Service’s deputy assistant regional director of external affairs. “It’s a reflection of the overall budget situation at the federal level.”

Yoshioka says she’s grateful for the all the support PEPP has been receiving from the federal government. Her plan now is to try to find more private donors who’re willing to invest in PEPP’s conservation mission. Winning this extinction battle requires money. “Most people in the United States don’t realize how close to extinctions these plants are,” Mehrhoff says. “They need to know that there’s a fight going on out here and money helps that fight a lot.”

The first step is to make people aware of the program, Yoshioka says, to make sure they understand why unique plants like Psychotria grandiflora and Brighamia insignis are worth saving. And it’s not just them, either. Native animals like insects and birds need the plants as a source of food. Without the plants, the animals go. “They’re part of one ecosystem,” Yoshioka says. “It’s the circle of life, we can’t have one without the other.”

Update May 17th, 2017 5:55PM ET: The story has been updated to include more information about PEPP’s budget.