Fig. 3. A, Section of leaf imaged by epifluorescence microscopy with blue light excitation showing peltate glandular trichomes (PGT) embedded in epidermis (E). The trichomes and their contents contribute to the yellow/green autofluorescence; the red autofluorescence is emitted by chlorophyll. B, Autofluorescence of glandular trichome imaged with UV excitation. Note the characteristic shape of the trichome as defined by the elevated cuticle (EC), the presence of lipid (L) and aqueous (Aq) secretions accumulated in the sub‐cuticular space, the relatively intense blue/white autofluorescence of the stalk cell (St) wall and the apparent absence of intact secretory cells. Cl, Red autofluorescence of chlorophyll.