A small wildflower growing across California may help scientists understand how plants can survive a changing climate—and even offer clues for protecting other species in the future.
The mountain jewelflower (Streptanthus tortuosus) grows in many different environments, from the rolling hills of wine country to the snowy slopes of the Sierra Nevada.
At first glance, it appears remarkably adaptable.
But researchers at the University of California, Davis have discovered that this and other jewelflower species may be far more vulnerable to climate change than they seem.
For the past decade, scientists have been studying California’s jewelflowers to understand how they evolved to survive in such different climates.
Their goal is not only to protect these flowers but also to learn lessons that could help conserve many other plant species facing similar challenges.
Climate change is altering California’s weather patterns. Rain and snowfall are becoming less predictable, and the wet season is arriving later than it did decades ago. Rains that once began in October often now arrive in November or even December.
This shift may sound minor, but it can have major consequences for plants. Many annual plants depend on seasonal rainfall to trigger seed germination. If the rains come later, seeds sprout later as well.
Surprisingly, this means that in a warming world, many plants are actually beginning their growth during colder and darker parts of the year. Researchers found that delayed rainfall reduced germination rates in most jewelflower species they tested. Plants that germinated later also produced fewer seeds by the end of the growing season.
Since seeds are the only way annual plants pass their genes to future generations, producing fewer seeds could eventually threaten their survival.
Scientists have also uncovered an interesting strategy that some wild plants use to cope with uncertainty. Certain desert flowers produce seeds that remain dormant for different lengths of time. Some sprout after one year, while others may wait more than a decade. This “bet-hedging” strategy ensures that at least some seeds survive if drought wipes out an entire generation.
To better understand how jewelflowers adapted to different climates, researchers examined nearly 2,000 preserved plant specimens collected between 1898 and 2016. These historical records revealed something unexpected. Although jewelflower species grow in deserts, foothills, and mountains, they all seem to prefer remarkably similar temperature ranges during growth.
Instead of adapting to different temperatures, each species has evolved unique ways of timing its germination and reproduction so that growth occurs within a narrow temperature window. They rely on environmental signals such as soil moisture, temperature, daylight hours, and winter chilling to know when to grow.
The problem is that climate change is disrupting those signals.
To help plants adapt, researchers are now exploring a strategy called assisted gene flow. This involves introducing genes from populations already adapted to warmer and drier conditions into populations that are struggling.
Scientists have even sequenced the first jewelflower genome and are developing new technologies that can identify climate-adapted plants by analyzing the way their leaves reflect light. In the future, drones, aircraft, or satellites could potentially scan entire landscapes to find plants best suited for changing conditions.
The researchers hope that what they learn from these humble wildflowers can help protect California’s forests, grasslands, and native ecosystems for generations to come.
