Princeton’s campus is lush with a variety of flora; as winter settles in and begins to replace fall, leaves are scattered around the grounds, their characteristic pale green and yellow coloration signs of seasonal change. This leaf was found in Princeton’s Mathey courtyard nestled in a patch of wet grass.


 As is visible in the above picture, the leaf has likely been subjected to the windy conditions judging by the dirt, holes, and broken edges pictured. This leaf was identified by the Seek app as a Small-leaved Lime (Tilia cordata), a species native to Europe but that has been widely planted in the United States as an ornamental tree.

The Foldscope captured a concentration of small, tubular entities on the leaf’s surface; these are most likely the trichomes, defined by Wikipedia as fine outgrowths on plants. These appendages serve a variety of purposes: trichomes belonging to cannabis plants, for example, are a defense mechanism protecting the plants from predators. For other plants, trichomes are useful in catching prey. The Small-leaved Lime has nectariferous trichomes that attract pollinators, specifically bees (https://www.researchgate.net/publication/273632978_Preliminary_studies_on_the_structure_of_sepals_and_trichomatous_nectaries_in_flowers_of_Tilia_cordata_Mill). As the weather begins to get colder, bees and other pollinators are not as active as the trees and flowers begin to prepare for the season ahead. The grassy Mathey courtyard is covered in leaves, each of which have slightly different coloration, perforations, and other damages; I am curious about the influence that organisms — in addition to the impact of weather conditions — had on the tree debris once fallen.

Note: I conducted this project as part of Professor Pringle’s EEB321 class at Princeton University.