The white Toyota Tacoma pounded down the dirt path, going up and down the hills, scraping the brush on the sides of the truck with a shrill whine. Naomi Frago, with pigtails under her hat, rode like a slightly more cautious Indiana Jones, guided by an ancient map.
She stopped the car on a hill overlooking an expanse of boulders and Joshua trees in eastern Kern County, about 170 miles northeast of Los Angeles.
“It’s right where they need to be,” she said.
Dr. Frago, 43, was looking for treasure, but not gold and jewels. She scoured the desert for the delicate flowers, so small they are called “belly flowers” because botanists must lie on their stomachs to view them properly.
This winter’s unrelenting rain has created an abundance of flowers across California this spring, delighting residents with vibrant colors at places like the California Poppy Sanctuary in Antelope Valley, where visitors lined up to take selfies with the displays. After such unusually wet periods, species appear that have not been around for many years.
For Dr. Frago, a botanist at the nonprofit California Botanical Garden in Clermont, this spring presents an unusual opportunity to document the existence of rare plant species to save them from the brink of extinction.
This stretch of Central California, where the Sierra Nevada Mountains merge into the Mojave Desert, was once part of a vast, untouched landscape. Billions of microscopic seeds lay dormant in the topsoil for years, even decades, until the right conditions were created for them to emerge as wildflowers.
Historically, spring has been marked by a dazzling variety of flowers in the West, each suited to its environment. (California, one of the most diverse places on the planet, is home to at least 2,400 rare plant species.)
Over time, farms, houses, and off-road vehicles have chipped away at patches of rare plants—here a hillside, there a meadow. Climate change has changed when, where and how much it rains. Even in places where carpets of wildflowers still flourish in wet years, crowds can threaten their future.
So this spring and summer, Dr. Frago and other rare plant biologists are engaged in an exciting race to find the wildflowers before they disappear again.
The ultimate goal of botanists is to secure an endangered or rare species designation for the most threatened plants. This could lay the groundwork for legally forcing land managers to make accommodations for endangered species. (For example, the Center for Biological Diversity has made protecting wildflowers a key part of its ongoing fight against the Taejon Ranch development, where nearly 20,000 new homes have been proposed north of Los Angeles.)
In order to obtain endangered or rare species, Dr. Frago and her colleagues must first prove that the plants still exist. Dr. Frago may be the only person able to do that for the plants she studies, said Kathy Heinemann, vice president of the Center for Plant Conservation.
“Without her, there would be no knowledge of these plant species in the whole world,” she said. “That’s what drives conservation: there are people who are fully equipped to look at these plants in the field.”
On this trip, Dr. Frago was looking for a species known as the Kelso Creek Monkey Flower, with flowers that are half golden yellow and half deep maroon.
“We all have our pets,” Dr. Frago said. “I just wish we could do more. We keep talking about the extinction crisis, but we only know if things are going extinct if you track them.”
Dr. Frago sees the widespread acceptance of habitat destruction in California as something of a slippery slope. Each flower represents millennia of evolution. If we accept the disappearance of one incomprehensible monkey, she worries, how it might end? And what are the consequences of the destruction of complex ecosystems?
Every spring, Dr. Frago and her fellow conservationists, including botanists who use apps like iNaturalist, try to document as many rare plant populations as possible.
Scientists must meticulously plan their search for prime targets. If they arrive too early, the flowers may still be in bud, making them more difficult to study. If they arrive too late, the flowers may already shrivel from the heat.
Dr. Frago settled on monkeyflowers after stumbling upon a career in science she never thought she would have.
Her father, a Mexican immigrant who worked as a truck driver, thought she should become a kindergarten teacher after she became the first in her family to go to college. But at age 20, a teacher—also Mexican American—took her on her first trip to hunt for a rare herb. Her feet hurt from the ill-fitting boots, but she hung on. Dr. Frago later felt the thrill of the discovery; she found five new species of monkey flowers.
As a Latin American, Dr. Frago is a pioneer in a field long dominated by whites, beginning in the 1700s when European colonists traveled the world and created collections of exotic plant specimens, many of which are used by scientists today. (The oldest specimen in the collection of the California Botanical Garden dates from 1750.)
“It’s a complicated legacy,” she said, pausing near a patch of purple clover, a native wildflower.
Later on the path, Dr. Frago spotted clusters of cream-colored desert dandelions and a bud of scallions and raced past rows of pale cream cups. Insects buzzed and lizards ran across her path.
She suddenly stopped. “Oh God! Hybrid!” she shouted.
The Kelso Creek Monkey Flower somehow crossed with the Rock Jasmine Monkey Flower, another closely related species. She had never seen him in person before. She stopped to take a picture plant and make detailed notes about its features.
“Actually, you’re coming with me,” she said, spotting another. She carried the plant back to the truck, where she tucked it between the pages of the Claremont Courier.
But the Kelso Creek Monkey Flower, her target for the day, was still proving elusive. She frowned in confusion. “It’s a good habitat,” she said.
She met up next to three of her students, and the group piled into two trucks. They splashed through the shades of Kelso Creek, for which the flowers are named, to check another spot where Dr. Frago had seen a small bloom of several hundred plants last year.
Beyond the stream, they saw a field that looked like green bushes and cacti from afar. But as they approached, the botanists looked in amazement: a sea of small plants with yellow-burgundy flowers was rolling ahead. The group later estimated there were millions.
“It’s a micro-super bloom!” – gasped Courtney Matzke, 35 years old, one of the students.
They finally found their flowers. The sun set in the afternoon.
It’s time for Dr. Frage and her students to get to work.