Unifacial leaf of a non-grassy monocot: Iris

Has similar tissue organization at both surfaces

A cross-sectioned iris (Iris sp.) unifacial (or isobilateral) leaf blade with a row of vascular bundles under each epidermis. The blade is flattened and is oriented along the vertical axis of the plant. The leaf has an unusual anatomy.

In the central portion of the blade shown here, vascular bundles in both rows are oriented with their xylem facing the inside of the leaf.

There is only an abaxial side, which is on both sides. The adaxial side is fused--hence the alternating orientation of vascular bundles.

1 = an epidermal papilla, 2 = sclerenchyma, 3 = phloem, 4 = xylem, 5 = lysigenous slime cavity, 6 = homogeneous mesophyll