The mesomorph leaf type is found in almost all plants from zones with a moderate climate. By clicking on the thumbnails views larger images can be obtained as well as further explanations about the microscopic sections. The two upper species (lilac and petunia) show the mesomorphic basic anatomy with some variations. The third species, Ivy, has besides mesomorphic characteristics also xeromorphic properties.
Mesomorph Angiosperms: Lilac (Syringa vulgaris)
Cross-section throug the leaf
Stained cross-section through the leaf of lilac: 1 upper epidermis, 2 palisade parenchyma, 3 spongy parenchyma, 4 air cavity, 5 lower epidermis, 6 stomata, 7 trichome, 8 major vein, 9 xylem, 10 phloem, 11 supporting tissue (sclerenchyma)
Suggestion for a tutorial project: using the above photograph with labels and descriptions, try to find similar structures (e.g. stomata) in the zoomable image here below
Ivy (hedera helix is known for combining xeromorphic and mesomorphic characteristics. Ivy grows in woody ans shady environment where high humidity would be expected. However, ivy is an evergreen that carries its leaves throughout the relatively dry winter. Although the leaf is largely mesomorphic, it shows some typical features of xeromorph species, i.e. the surface is covered by a leathery cuticula and the tissues are very compact.
