cross section: Syringa leaf magnification: 100x

The upper and lower epidermis are uniseriate with a thin waxy cuticle. Stomata are abundant on the lower or abaxial surface and may occasionally be seen on the upper or adaxial surface as well. Small mushroom shaped peltate trichomes are also present in the lower epidermis. These secretory trichomes have short stalks, appearing to sink into the epidermis.

A large upper palisade mesophyll is composed of two layers of elongated, densely packed photosynthetic parenchyma interrupted by an occasional substomatal air spaces. A smaller lower spongy mesophyll is composed of aerenchyma; loosely arranged photosynthetic parenchyma with abundant air spaces.

Both midrib and smaller vascular bundles in the blades are collateral with large thick-walled xylem vessels towards the adaxial surface and smaller sieve tubes and companion cells of phloem towards the abaxial surface of the leaf. A largely parenchymatous ring of bundle sheath cells is present but difficult to distinguish in all but the smallest vascular bundles.