Stem and its types

general description of stem

1. SUBJECT: Morphology of vascular Plants Semester: II, BS Botany Teacher Name: Dr. Khalid Rasheed Khan Department of Botany Government College Mansehra

2. Lecture No.02 Stem: Definition and its morphology

3. Stem The portion of the primary axis of plant which develops from plume of seed. Types of plants on the basis of growth 1.Annual e.g wheat, Tomato 2.Biennial e.g radish, Turnip 3.perennial all woody plants e.g Mango, Apple

4. Types of plants on the basis of structure of stem 1.Herb: soft and usually green stem e.g tomato 2.Shrub: woody main stem can not be distinguished from its branches e.g rose 3.Tree: perennial woody plant with distinct upright stem e.g mango

5. Descriptive terms of stem Herbaceous: soft and green stem e.g tomato Woody stem: hard woody stem e.g mango Fistular stem : internode of the stem are hollow e.g Bamboo Solid stem: stem is not hollow e.g apple Jointed: many nodes on stem e.g Grasses Cylindrical: straight and rounded stem e.g Rose Flattened: flat stem e.g Opuntia Succulent: Thick and fleshy stem e.g Euphorbia Hairy: stem having hairs e.g Sunflower Spiny: stem with spines or throns on its surface e.g Acacia

6. Types of stem Aerial stem Underground 1.Reduced aerial 1.Rhizome 2.Erect Stem 2.corm 3. Weak stem 3.Bulb 4.Stem Tuber Climbers Trailers 1.Twiners 1.creepers 2.Tendrils climbers 2.Runners 3.climbershook climbers 3.Stolon 4.Climbers 4.offset 5.Suckers

7. Thank you