John Muir is widely known for his towering environmental achievements -- as the Sierra Club founder, father of the national park system, and champion of California's redwood forests and Yosemite Valley.

He also looked at the small stuff in nature -- plants and flowers.

Muir's much-overlooked role in collecting, discovering and cataloging plants is getting fresh attention in a photography exhibit that opened this weekend at the Bedford Gallery in Walnut Creek and will continue until March 27 before going on a national tour.

Muir, an 18th and early 19th century naturalist, writer and conservationist, spent decades collecting plants in his treks around the country. He often mailed the dried specimens and notes about them to friends, family members, artists and fellow botanists.

Pleasant Hill photographer Stephen Joseph and Yosemite Valley historian Bonnie Gisel spent five years tracking down those specimens from museums and scientific storage rooms and then using modern cameras and computers to restore the images to their former glory.

The result is a collection of bold and big photographs -- some up to 7 feet tall -- that show in exquisite detail the small wild lilies, ferns, leaves and pinecones collected by the Martinez resident who become America's most famous naturalist.

"Plants drove John Muir. Plants are the main reason that John Muir got out and made these journeys to experience nature, and motivated him to protect it," said Joseph, a natural landscape photographer and teacher who specializes in large panoramic shots of Mount Diablo in central Contra Costa County. "People think of Muir for protecting Yosemite Valley and creating the national park system, but few look at him as an important botanist."

To Muir, the tiny spores in ferns or delicate petals of wild lilies were a window into nature's awe and beauty as much as the tall waterfalls and giant granite cliffs of Yosemite Valley. Muir gave Theodore Roosevelt a personal tour of the park in 1903, which inspired the president to make the valley the first national park.

"Were not all plants beautiful? Or in some way useful?" Muir wrote. "Would not the world suffer by banishment of a single weed?"

Muir said plants shielded him from loneliness in his often solitary treks. Finding a rare wild orchid in a Canadian swamp made him weep and was one of the high points of his life, he wrote.

Joseph and Gisel share Muir's appreciation of plants, but realized that creating a book and photo exhibit on Muir's botanical specimens was an enormous undertaking that would challenge them like nothing else their careers. Each has more than 25 years experience in their field.

"Muir's plants were stashed all over the place," said Gisel, a Muir scholar, author of two books on him, and curator of the Sierra Club's LeConte Memorial Lodge in Yosemite Valley. "Muir would tuck them in a book, or in his Bible, and later mail them. He never saw some of these pressed plants again."

Locating Muir's plants was a detective job. The specimens were in deep storage at museums, historical sites, and plant repositories, known as herbariums, along with tens of thousands of other preserved foliage kept in folders sorted by the names of the specimen, not of the person who collected them.

Gisel scoured Muir's journals, letters, and notes to compile a list of what Muir collected. Then she traveled to UC Berkeley, Harvard University, and several other universities and museums in other states and spent weeks finding Muir's plants and flowers. The Muir National Historic Site in Martinez -- site of Muir's home -- also offered the researchers access to their specimens.

"It was exhausting," said Gisel, who is accustomed to rough conditions. She lives in a tent in Yosemite for six months a year with her Scottish terrier named Atwood. "It was also magical to realize that these were the plants that John Muir collected. For Muir, these were like living postcards."

Joseph faced his own challenge. He had to scan high-resolution images of more than 600 dried plants. Then he returned to Pleasant Hill and spent more than two years restoring 177 images of the specimens to their likely appearance when Muir first dried and preserved them.

"Some of the plants were a mess," Joseph recalled. "They were torn, gray, faded, eaten by bugs. They were sprayed with chemicals, stored on acidic paper, and taped over. Our earliest plants were from 1864 when the Civil War was still going on."

Joseph spent up to 20 hours to restore a single image. He added contrast, modified hues, filled in missing parts of leaves or petals. He digitally removed background paper and plastic covering some sites used to protect the plant.

The result turned the micro-world of small wild plants into macro art. "I want to take the invisible and make it visible," Joseph said.

Twenty three plant images are on display in the exhibit, along with some of Muir's sketches and magnified excerpts from his journals. The exhibit will travel to locations around the nation this year and then make a stop next year in Dunbar, Scotland, where Muir was born in 1838.

Joseph and Gisel said they expect their exhibit to appeal to fans of gardening, art, history, photography and science.

Without plants, Gisel said, there would be no humans on earth.

As he stood beside one of his 7-foot-tall photographs, Joseph said, "You can't help but feel excited that this is the plant that John Muir picked."

Contact Denis Cuff at 925-943-8267. Follow him at Twitter.com/deniscuff.

IF YOU GO
What: "Nature's Beloved Son: Rediscovering John Muir's Botanical Legacy"
When: Continues through March 27. An opening reception with Stephen Joseph and Bonnie Gisel is from 6 to 8 p.m. Thursday. Admission is $5.
Where: Bedford Gallery in the Dean Lesher Regional Center for the Arts, 1601 Civic Drive, Walnut Creek. Hours are noon to 5 p.m. Tuesdays through Sundays and 6 to 8 p.m. when the center has performances.
Details: http://bedfordgallery.org