Prelab 5 Botany and Medicina l Plants Introduction

Prelab 5 Botany and Medicina l Plants Introduction Of Leaves (201) Medicinal Plants (PGC 101) First Year Students

Scheme for description of the surface preparation Items Upper Epidermis Drawing 1. Shape of Cells 2. Anticlinal walls 3. Cuticle 4. Stomata 5. Hairs 6. Content Lower Epidermis Drawing

Hairs (Trichromes) Definition • They are protrusions or extensions of the epidermal cells which vary in size , shape and characteristics. • The protrusion may be very short and conical so called papillae. Hair Composition It consists of: Arising from cicatrix a. Foot : base b. Body: free part. Embedded in the epidermis

Hairs (Trichomes) Functions v Protection. v To decrease transpiration in desert plants. v Glandular hairs secrete resin and oleoresin. Importance Identification of leafy drugs and determination of species and genera. 2

Hairs (Trichomes) Classification Glandular Non-glandular Head Stalk Each type to be classified according to : Number of cells Type of branching Unicellular Multicellular Branched Non-branched Number of rows Uniseriate Biseriate Multiseriare

Non glandular hairs Unicellular Multicellular Branched unbranched Cystolith hair in Cannabis. Warty hair in Senna. ( with enlarged base containing Ca. Co 3)

Non glandular hairs Unicellular unbranched Multicellular Branched

Non-glandular multicellular, unbranched Uniseriate In Stramonium. Biseriate hair in Calendula. Twin hair in Arnica. (Bicellular biseriate) Multiseriate (pluriseriate) Shaggy hair in Cumin.

Non glandular hairs Unicellular unbranched Multicellular Branched

Non-glandular, Multicellular, Branched 1. Peltate hair in Olea. With very short axis surmounted by a plate-like structure of closely joined cells. 5 2. Candelabra hair in Verbascum. With uniseriate axis from which arise numerous unicellular branches.

3. Stellate hair in Tilia. (With radiating unicellular branches) 4. Digitate hair in Lavender.

Glandular hairs Head Stalk Glandular hair with head and stalk

Glandular hairs with Unicellular, Unbranched stalk Unicellular head Bicellular head In Digitalis 7 Multicellular head A. Clavate hair in Stramonium

B. Labiaceous hair in Mentha. with unicellular stalk & multicellular head with 8 -16 radiating cells. Top view Side view Basal view

Glandular with multicellular unbranched stalk Uniseriate Biseriate In Belladonna Compositae hair in Chamomile. Multiseriate (pluriseriate) Shaggy glandular hair in Cannabis. S. V. T. V.

Glandular with multicellular branched stalk Glandular Branched hair in Hyoscyamus