A little purple wildflower changed Katy Chayka's life.

The time was late summer a few years ago, and the place was a regional park near her home in New Brighton, where she was taking a walk. "A spot of color caught my eye. I thought, 'What a pretty flower.'"

She didn't know what it was, so she got a field guide. The flower turned out to be a New England aster. But identifying other wildflowers, Chayka discovered on later walks, wasn't so easy. "I'd see a plant and try to look it up. Not there," she said. "Then I'd see another one. Not there."

She scoured other field guides and websites, and found most of them disappointing. "The problem with books is that there's only so much information you can cram into them," she said.

The websites she found weren't specific to Minnesota, and were lacking in photos. "You can't just look at a mugshot of a flower. You have to see the leaves and how they're arranged on the stem," she said.

"I thought, 'Somebody's got to do something.'" So Chayka, a freelance Web consultant, took on the job herself.

She's now the founder and creator of Minnesota Wildflowers, an online field guide (www.minnesotawildflowers.info) that details nearly 500 native wildflowers. The site has become a go-to resource for many, logging 1.2 million hits last month, she said.

Chayka's field guide fills a vacuum, said Welby Smith, botanist with the Minnesota Department of Natural Resources, which links to Chayka's site on its site. "There's tons of stuff online, but most is junk, irrelevant or not helpful," he said. "Without Katy's website, it could be overwhelming to beginners. For identifying Minnesota wildflowers, it's the best thing. It's great."

Along the way, Chayka acquired a collaborator, Peter Dziuk, a native-plant advocate she met on a Minnesota Native Plant Society field trip. Dziuk donated 50,000 photos to the project.

Now Chayka has set her sights higher: to catalog every plant that grows in Minnesota, an estimated 2,100 species.

To that end, she spends at least 20 hours a week in the field: traveling the state, prowling for plants, recording information and collecting photos.

It's a labor of love. ("There's no money in wildflowers," she said.) But after years of financing the quest herself, she's started to look for sponsors and has begun selling wildflower-themed products, such as notecards and screen savers. "I'm thinking about a coffee-table book," she said. "This isn't going to be a cash cow, but I'm hoping to get some financial support."

She hasn't kept track of what she's spent so far, but she estimates it costs her $30 per species to collect new images. She keeps her field-trip expenses as low as possible by camping.

'Allergic to the outdoors'

What drives her to invest so much of her time and resources in such an arcane pursuit? Surprisingly, not a lifelong love of plants.

"Heck, no! I was allergic to the outdoors," said the native New Yorker. "But I had put on a little weight; that's why I started walking. Boom! There it all started."

She's now captivated by the wide variety of plants in Minnesota. "There's so much out there, and every two weeks, it's a different group of plants," she said. "It's endlessly fascinating."

At Long Lake Regional Park alone, where she first spotted that New England aster and now does plant surveys for the city as a Master Naturalist volunteer, there are almost 350 different plant species. But she's concerned that many of Minnesota's native plants are endangered, which is why she's made it her personal mission to chronicle and protect them. (Her tagline is: "A Project for Environmental Justice.")

"What drives me, the more time I spend in the field, is that non-native species like buckthorn and garlic mustard are taking over," she said. "We are losing so much of our native species to invasives and development." The result is that bees, birds and other creatures increasingly are unable to find food or habitat.

Part of her mission is to steer gardeners away from aggressive non-native plants toward native plant species.

"Our native flowers are as gorgeous and varied as anything you'd find in a nursery," she said. "It's about finding the right natives to take the place of non-natives, so people have good alternatives."

As far as Chayka is concerned, any plant not native to Minnesota, even if it's beautiful, is a weed. "If it's not native, don't plant it -- pull it," she said.

Chayka's field guide is "an invaluable tool," said Julia Vanatta, publicist for the Twin Cities chapter of Wild Ones, a nonprofit environmental education and advocacy organization.

"A lot of changes are happening rapidly, with weather and development taking away the natural landscape," Vanatta said. "Ten years from now, as rapidly as weather patterns are changing, some of these species will no longer be here." Chayka is creating a database that documents current conditions and will aid in future restoration, she said.

Chayka hopes it doesn't come to that, and she wants more Minnesotans to share her sense of urgency.

"We are heading toward losing it all," she said. "You don't realize what you've got till it's gone -- and then it's too late."

Kim Palmer • 612-673-4784