By Isabella Lin, Ryan Gabelman, Hillary Poalacin, Luke Sparreo

Apr 28 2026

The false turkey-berry (Plectroniella armata), native to Southeast Africa, is a spiny flowering shrub that bears an orange-colored fruit. The leaves of P. armata develop domatia, small structures found on the bottom of leaves often formed by cavities and/or hairs located between the main veins of a leaf. These domatia effectively function as homes for mites and their eggs, many of which are predatory towards fungi that could otherwise harm the plant. In this mutualistic relationship, P. armata provides domatia as shelter for mites, and in return, those fungivorous mites protect the plant from disease. Interestingly, researchers have uncovered that the domatia are made up of folds on an ultrastructural level. These folds create a greater surface area within the domatia, a structural feature that normally functions to facilitate the exchange of materials. Additionally, P. armata’s domatia contain large numbers of stomata, which act like a plant's pores to the environment, and hairs that create a more suitable environment for resident mites. Due to these many interesting features, it is unknown which of these exaggerated structures the leaves of P. armata evolved to function as a means of maintaining the presence of mites in their domatia.