Looking at a leaf through a magnifying glass, a complex web comes into focus. Thick, dark lines shoot off shorter, lighter lines, which give way to those even more transparent and diminutive. This is called the vascular system and it allows plants to distribute water and perform photosynthesis.

Eleni Katifori, an assistant professor in the Department of Physics & Astronomy in the School of Arts & Sciences, and graduate student Tatyana Gavrilchenko study this network. For six weeks this summer, they had help from rising high school juniors Amber Hymes-Vargas and Gina Maître, who collected, bleached, dyed, scanned, and skeletonized leaves.

Hymes-Vargas and Maître participated in a unique summer program called the Penn Laboratory Experience in Natural Science, or Penn LENS. For three years, it has invited local students to conduct research with professors like Katifori to gain hands-on experience and exposure to life as a scientist. What started as two interns in the lab of Alison Sweeney, also an assistant professor of physics and astronomy, has morphed into eight students in six labs across disciplines.

“Our focus from the get-go was on students from Philadelphia public and public charter schools. We were looking specifically for underrepresented minority kids. Right now, we’re an all-female program,” says Jane Horwitz, director of Penn’s Science Outreach Initiative. “We wanted students who might not otherwise have these opportunities.”

Desislava Todorova, a postdoctoral researcher in the Katifori lab who worked with the students over the summer, says she believes Penn LENS is a great way to introduce teenagers to high-level science in a positive, encouraging setting.

“It helps them feel more confident being in a lab, feel confident doing research, and communicating their ideas to fellow students and to other scientists,” she says.

Listen to the participants speak about their research, and it’s clear that Penn LENS is succeeding. Sixteen-year-old Fatmata Fahnbulleh, who worked this summer in the Department of Chemistry, describes in detail the intricate process for separating and recycling metals. Maître talks animatedly about maple and horse-chestnut leaves.

“This is what a leaf venation looked like millions of years ago. It’s not very effective because if a bug took a bite out of this section here,” she explains, pointing to one image, “this whole section would die because the networks wouldn’t be able to get nutrients to the other parts of the leaf.”

At the program’s culmination, participants presented their work in a poster session. Excited students shared their results with a room abuzz. As the event concluded, Hymes-Vargas handed Todorova a gift to thank her for the experience: It was a plant, a reminder of the very work that brought them together.