Demonstration that flavone aglycones accumulate in the peltate glands of Mentha x piperita leaves

In Mentha x piperita leaves, the peltate glands may be divided into two types according to the presence or the absence of crystals in the head of the trichomes. In both types, the free lipophilic flavonoid aglycones, characterized by UV and chromatographic data, are located in the head of the peltate glands, together with monoterpenes.