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