Define the inner structure of a dorsiventral leaf by using a labeled diagram.

Dorsiventral leaves are found in dicots. The significant anatomical characteristics of dorsiventral leaves are discussed below:

(a) Upper epidermis: This is usually the outermost single made of parenchymatous cells. The epidermal cells have sometimes outgrowths known as papillae, e.g., in Gladiolus. The epidermal cells are devoid of chloroplast and stomata are absent on the top epidermis.

(b) Lower epidermis: It is the same as the upper epidermis but here stomata are present. Chloroplasts are absent in the bottom epidermis also, except the guard cells of stomata.

(c) Mesophyll: In between the lower and upper epidermis mesophyll tissues is present which can be split into two regions:

i. Palisade parenchyma: These are lengthened columnar cells without intercellular spaces. These contain chloroplast in them and are usually arranged in two layers.

ii. Spongy parenchyma: It is found below palisade parenchyma and is oval or spherical with intercellular spaces. They also contain chloroplasts but several chloroplasts are more in palisade parenchyma than spongy parenchyma.

(d) Vascular bundles: Vascular bundles are usually found at the boundary between the spongy and the palisade regions. The vascular bundle in the midrib area is the largest. Vascular bundles are collateral, conjoint, and closed. Each vascular bundle is encircled by a bundle sheath of parenchymatous cells. In the vascular bundle, phloem is found towards the lower epidermis and the xylem is present towards the top epidermis. Additionally, in the xylem, the protoxylem is towards the uppermost epidermis