Internal Structure of Stem

By: Ivan Jeremy V. Guerrero

Epidermal Tissue

Stems are surrounded by a transparent epidermis that is usually one cell thick and often bears trichomes.

Trichomes of tomato plant secrete an irritating juice that deters hungry insects, while hooked-shaped trichomes often entangle insects and prevent them from feeding while they struggle to free themselves.

Vascular Tissue

Vascular bundles are often enclosed by or associated with schlerenchyma fibers that differentiate after the internode has finished elongating.

Vascular tissue

Vascular bundles are as follows: monocots have vascular

bundles embedded s throughout in the ground tissue.

Dicots have vascular bundles embedded in a single ring in ground tissue.

Gymnosperms and some dicots have concentric cylindrical vascular bundles: the phloem surrounds the xylem.

Ground tissue

Between the epidermis and the vascular tissue is the cortex. Most cortical cells are parenchyma; also, some are photosynthetic.

In dicots, parenchymatous ground tissue in the center of the stem is called the pith. These pith are lignified & specified for storage.

Ground tissue

Monocot vascular tissue are found throughout the stem, so ground tissue in monocots are not discernable as pith or cortex.

Parenchyma in monocots are simply called ground tissue.