Standing in front of a packed room at the Missouri Botanical Garden, the Garden’s new president and director, Lúcia Lohmann, introduced her audience to the tallest tree in the Amazon rainforest.

Dinizia excelsa towers over the treeline at nearly 90 meters (300 feet) tall. Yet, despite its stature, this behemoth went undiscovered until 2019, when it appeared in satellite images as part of a 3D mapping project. It took three years and multiple failed expeditions for scientists to finally reach the tree by foot and study it directly.

“If a tree that is 300 feet tall was only discovered a couple of years ago,” Lohmann said, “imagine how much biodiversity is still there to be discovered in the Amazon.”

More than 250 people attended Lohmann’s address as part of Tropical Forest February, an event series presented by the Living Earth Collaborative as part of the WashU Center for the Environment's Environmental Research and Creativity Week 2025. The talk served as a public debut for Lohmann, who earlier in the year assumed her post as the Garden’s eighth president and director – making her the first woman to hold that position. Her hire includes a dual appointment in WashU’s Department of Biology as the George Engelmann Professor of Botany.

“She is a world-class leader in plant science and conservation,” said Feng Sheng Hu, the Richard G. Engelsmann Dean of Arts & Sciences, during his introduction of Lohmann. “Her return to St. Louis is not only a major milestone for the Garden, but also a tremendous win for WashU.”

Lohmann’s keynote on the flora and fauna of the Amazon was an opportunity for her to demonstrate her impressive expertise on the planet’s most biodiverse hotspot. But it’s the sizable knowledge gaps about the Amazon that continue to make it a magnet for scientific research.

“In one hectare of Amazon rainforest, we have more species than we have in the entirety of Europe,” Lohmann said. “So, needless to say, there’s lots of really interesting biodiversity, and we estimate that only 10% of it has been described.”

Lohmann’s drive to catalogue even more of those species first brought her to St. Louis and the Missouri Botanical Garden in 1993, back when she was still an undergraduate at the University of São Paulo, Brazil.

“I was working on a field guide of the Ducke Reserve, which was the first field guide of plants in central Amazonia,” Lohmann recounted to the audience. “We didn’t have a well-curated collection in Brazil, so I came to the Garden to identify those materials. When I started working on the guide, they told me, ‘It’s going to be easy. There’s 15 species. We’ve been collecting in this place for 30 years now. We know them all.’ When I finished the guide, it had 150 species. So, just another reminder of how little we still know.”

With a full house of attendees representing dozens of different organizations, the event served as another major step for the Living Earth Collaborative, a productive partnership between WashU, the Garden, and the Saint Louis Zoo.

“One organization can only do so much to impact the world,” said Dwight Scott, the Dana Brown President & CEO of the Saint Louis Zoo, in his opening remarks. “But together, through partnership and collaboration, we can achieve our potential. That is why I believe in the Living Earth Collaborative.”

The Tropical Forest February series included a morning event where guests could learn about the unique plants found in the Missouri Botanical Garden’s Climatron from Mónica Carlsen, an assistant scientist and education coordinator at the Garden, followed by self-guided tours of St. Louis’s only tropical forest. Staff from the Garden and the Saint Louis Zoo were on hand to provide visitors with information about tropical plants and animals.

Lohmann’s evening talk included several display tables featuring staff and researchers from the Garden, Zoo, and WashU. Projects included WashU research on apes in the Congo, Zoo information on responsibly sourced palm oil, and ongoing research efforts in Madagascar by all three partner organizations.

In addition to public-facing events like Tropical Forest February, the Living Earth Collaborative funds research projects that explore biodiversity in St. Louis and around the world. Its network of biodiversity fellows includes nearly 200 scholars and conservation practitioners at more than a dozen St. Louis institutions.