1. Dermal Tissues of Plants 1.Muhammad Hussaan Kamboh (M. phil Botany, Ph. D Scholar) & 2. ALI RAZA (M. phil Botany) & 3.Uzair Ashraf (MSC Botany)

3. Epidermal cell Defination Epidermal cells originate from the protoderm, cover all parts of the primary plant body. Cuticle The exposed outer walls have a cuticle that varies in thickness, depending on the species and environmental conditions. Various cell in epidermis guard cells( stomata) trichomes root hairs

4. 1) Stomata Stomata occur in the epidermis of leaves and sometimes on other parts of the plant, such as stems or fruits

5. Structure of stomata Guard cell is dumbbell-shaped cells flanking a stoma (mouthshape epidermal opening). Guard cells, unlike other epidermal cells, contain chloroplasts.

6. stomata No of stomata in plant leaf: There are between 1000 to more than 1 million stomata per square centimeter of leaf surface. Location of stomata on leaves: o In many plants, stomata are more numerous on the lower Epidermis than on the upper epidermis of the leaf o Offenly in many plant they are present on the lower side of leaf and a few, such as water lilies, have them only on the upper epidermis Function: The passage of oxygen and carbon dioxide, as well as diffusion of water in vapor form, takes place almost exclusively through the stomata.

7. 2) Trichomes Defination:Trichomes are hairlike outgrowths of the epidermis. Location: o They occur frequently on stems, leaves, and Reproductive organs. Function: o Trichomes play an important role in keeping the leaf surface cool and in reducing the rate of evaporation. o Some glandular trichomes often secreting sticky or toxic substances to deter herbivory

8. 3) Root hairs o Defination: o Root hairs, which are tubular extensions of individual epidermal cells, occur in a zone just behind the tips of young, growing roots. Function: o Root hairs keep the root in intimate contact with the surrounding soil particles and greatly increase the root’s surface area and the efficiency of absorption.