In a quiet corner of Maui Nui Botanical Gardens, set in a grove of kukui trees, is a bench dedicated to the late Rene Sylva, a renowned local conservationist. The view from the bench looks into lush Iao Valley, past the garden’s most mature collection of native greenery.

Sylva, a self-taught botanist, began planting kukui and mamane trees, kupukupu ferns, awikiwiki vines, kooloa ula shrubs and much more in that spot in 1976, when it was part of the 6-acre Maui Zoological and Botanical Gardens. He was the zoo’s groundskeeper.

"We owe a lot to Rene, who is remembered as the first person to champion the preservation of native Hawaiian plants," said Tamara Sherrill, Maui Nui’s manager. "When he passed away in 2008, an obituary in The Maui News noted that he did a lot to raise public awareness about the plight of these plants. He was a mentor to many individuals and groups involved in environmental work."

When the zoo closed in 1996, the nonprofit Maui Nui Botanical Gardens was established to protect and manage the native plant collection that Sylva had started. ("Maui Nui" refers to Maui County — the islands of Maui, Lanai, Molokai and Kahoolawe.)

The site was opened in 2001 "to foster appreciation and understanding of Maui Nui’s plants and their role in Hawaiian cultural expression by providing a gathering place for discovery, education and conservation."

"We’re the first botanical garden in Hawaii to focus on native plants," Sherrill said. "Hawaii is the most isolated landmass in the world, and our native flora evolved into something truly distinctive. More than 1,000 species evolved from a few hundred original ‘colonists.’ About 90 percent of our native flora aren’t found anywhere else in the world."

In addition to some 150 species of native plants, the garden propagates most of the two dozen Polynesian-introduced or "canoe plants" that Hawaii’s first settlers brought to sustain life in their new home. These plants were used for everything from food, medicine and clothing to shelter and weapons.

Through crossbreeding and natural adaptation, they evolved into hundreds of varieties suited to our varying climates and soils. For example, the garden grows 70 varieties of taro, 40 varieties of sugar cane, 30 varieties of sweet potato and 20 varieties of banana.

"Hawaiian plants are important because they are biologically unique and culturally valuable," Sherrill said. "They continue to be a precious source of materials for the lei, dyes, kapa, weaving, traditional medicine and hula implements and adornments of cultural practitioners. Most people aren’t aware that 354 Hawaiian species are on the federal endangered and threatened plant list because of invasive species, habitat destruction due to construction, and feral animals such as pigs, deer and goats."

The garden partners with conservation and community groups to support dozens of cultural and restoration projects each year. These efforts include reintroducing native species in the wild and providing plants and advice for school and community gardens. This year the huli (tops) of threatened Hawaiian taro varieties will be given to farmers on Maui.

"We also continue to work with researchers to document previously unidentified varieties of plants and add them to our collections," Sherrill said. "We’ve become a field site for job training and school groups. We’ve developed a close relationship with the University of Hawaii Maui College and public and private schools throughout the state, and have provided countless students with training and materials for educational projects."

Hiking with the Native Hawaiian Plant Society (www.hear.org/nhps) in 1999 piqued Sherrill’s interest. "I couldn’t figure out why the society’s members would hike for miles across a blazing, dry lava flow to see a single plant that looked like a half-dead weed," she recalled. "They were so thrilled to see it, it was like they had found gold!"

Realizing such rare species were disappearing every year, Sherrill knew she had to join the campaign to save them. "Native plants are the most challenging and interesting things I’ve ever grown," she said. "Some seeds won’t germinate in a nursery, but pop up like weeds all over the garden. Some plants grow beautifully on a barren lava flow but languish when fussed over in the garden. There are so many wonders and mysteries about these amazing plants, and it’s rewarding to be part of a team that’s dedicated to learning about and protecting them."