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ST. LOUIS – The Missouri Botanical Garden is known for its beautiful plants and flowers, but that’s not where you’ll find ecologist Matthew Austin.

Most days, you’ll find the post-doctoral fellow with Washington University’s Living Earth Collaborative combing the stacks, not of a library, but of the garden’s Herbarium, one of the world’s best research resources for all things plants.

“The garden has plant specimens from across the globe and dating from today through back more than a century,” Austin said.

Austin’s research focuses on how changing environments are affecting biology. His subject of choice? One of the first flowers we see when spring rolls around, blue violets.

“I’m interested in the common blue violet because this is a fantastic model species for how climate change has affected plant reproduction,” he said.

Unlike other plants, blue violets have two distinct types of flowers. One is the pretty blue flower that blankets backyards. That flower reproduces with the help of pollinators. The other flowers remain tucked away at the base of the plant and never see a bee or butterfly. They self-reproduce.

“By studying how climate change has affected the production of these two different flower types in the common blue violet, we can study how climate change is affecting plant reproduction broadly,” he said.

Austin and his colleagues looked at this mixed mating process using violet specimens from the Herbarium dating from 1875 to the present and paired that with temperature and precipitation data. And what did they find?

“Across the past century, we’ve seen violets produce more of the open, showy flower relative to the self-fertilizing flower,” he said. “And this appears to be driven by increased precipitation that Missouri has experienced across that time.”

The findings also suggest climate change might not just affect how plants reproduce, but also when. Showy violet flowers bloom earlier in the spring than in the past. But those flowers depend on bees that may not have emerged yet.

“Violets have shifted the time of year that they are flowering. And if their pollinators have not also shifted the time that they occur, then this could throw violets out of sync,” Austin said.

Austin calls the carefully collected and preserved plant specimens at the Herbarium crucial to science