Pterophyta - 9

The Epidermis has a cuticle and stomata. The stomata are generally on the lower (abaxial) surface.

Some species produce hairs or trichomes but in general fern leaves lack these.

Many species produce large multicellular Scales. These are generally found on the Petiole (Stipe) and Rachis.

The Leaf Mesophyll can be simple with uniform Chlorenchyma. However, the mesophyll can be just as complex as the most complex Angiosperm (Flowering Plants)

Pellaea Leaf Cross-section

Sporangia are borne on Leaves (Sporophylls). In some cases "fertile" leaves have the same appearance as vegetative leaves.

In other cases, some portion of a leaf is specialized for spore production.

Some species have highly specialized sporophylls which are very different from vegetative leaves.

Polypodium Leaf (Adaxial)

Polypodium Leaf (Abaxial)
The orange areas are Sori.

Fern with Dichotomous lobed Vegetative Leaf & a Spoon-like Sporophyll

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