Tala

1. Leaves - lateral outgrowth of the stem - flattened,expanded - leaf primordia - leaf buttress

2. Leaf Parts: Petiole - cylindrical part - attaches blade to the stem 2. Lamina or Blade - flattened green part Petiolated Sessile or apetiolated

3. Monocot leaf Supported by leaf sheath Ligules and auricles Functions: 1. protection from dirt water

4. 3. Stipule - two leaflike flaps of the petiole - dicot leaves a. Stipulate – w/ stipule b. Exstipulate – without 4 . Midrib - central vein 5 . Veins - conducting tissue of the leaf 6 . Veinlets - secondary veins 7. Margin - edge of the leaf

5. Simple leaf - one blade or lamina Compound leaf - blade is divided into two or more leaflets or ( pinnae ) - petiolule Rachis – continuation of the petiole where the leaflets are attached

6. Types of Compound Leaves A. Pinnately Compound - leaflets are arranged laterally along the rachis (featherlike fashion)

7. 1. Simple Pinnate a. Even pinnate - each leaflet has a pair b. Odd pinnate - terminal leaflet has no pair

8. 2. Bipinnate - primary rachis branches into secondary rachis that bears the leaflets 3. Tripinnate - with primary, secondary and tertiary rachises

9. B. Palmately Compound - leaflets radiate from a common point 1. Unifoliate - single leaflet at the tip of the stalk 2. Bifoliate 3. Trifoliate 4. quadrifoliate

10. PHYLLOTAXY

11. Phyllotaxy Alternate - one leaf at each node 2. Opposite - two leaves opposite each other at each node 3. Whorled/ verticillate - several leaves at equal distance around the node

12. 4. Spiral - leaves arise succeedingly around the stem 5. Decussate - two opposite leaves at right angles to the one below or above it

13. Shape

14. Margin

15. Leaf Venation

16. 2 Systems of Venation : 1. Reticulated/Netted - main vein branches - forms network a. Pinnately netted - main vein - veins and veinlets arise from the midrib and ramify throughout the lamina

17. b. Palmately netted - principal veins arise at one point at the base of the leaf

18. c. Radiately netted - principal veins radiate at the tip of the petiole Colocasiaesculenta ( gabi )

19. 2. Parallel/Striate Venation - veins are parallel with the midrib - common in monocots a. Radial Parallel - parallel veins form acute/right angles to the midrib

20. Diagram of Dicot Leaf

21. Dicot Leaf Cross section

22. Epidermis - upper and lower - single layer of cells - derived from protoderm Functions: a. Protects leaf from dessication –( cuticle ) b. Abrasion c. Prevents entry of fungi and bacteria d. Regulates exchange of gases (Oxygen and carbon dioxide

23. 1. Trichomes - protection against water loss 2. Stomata - more stomata in lower epidermis - high temperatures - high concentration of CO 2 close stomata

24. 2. Mesophyll - located between the upper and lower epidermis - dicots (2 distinct layers) a. Palisade mesophyll - arranged in compact columnar fashion - most photosynthetic activity takes place b. Spongy mesophyll - irregularly shaped - prominent intercellular air spaces - diffussion of carbon dioxide to other parts of leaf

25. 3. Vascular bundle/Leaf Vein

26. 3. xylem - part that faces upper surface of the leaf phloem - part that faces the lower surface of the leaf bundle sheath cells - for added strength and protection

27. Diagram of Monocot Leaf

28. Monocot leaf cross section

29. Internal Anatomy of Monocot Leaf Upper epidermis - covered with cuticle - bulliform cells - stomata present in upper and lower epidermis Guard cells monocot - dumbbell in shape Guard cells dicot - kidney shaped 2. Mesophyll - not differentiated into palisade and spongy mesophyll

30. Pine leaf cross section Cuticle - much thicker Epidermis - multilayered Mesophyll

31. Modified Leaves

32. Spines - modified leaves or modified stipules - for protection

33. Tendrils - slender, coiling structures - for support - exhibit thigmotropism (opposite side begins to grow rapidly )

34. b Bracts - modified leaves at the base of the flowers - colored bracts for attraction ex. Poinsettia bougainvilla

35. Uncutiniced leaves - for absorption ex. Digman

36. Expanded leaf like petiole - for additional photosynthesis ex. Pomelo

37. Fleshy and succulent leaves - for storage ex. Sabila

38. Plantlets at the tip of the leaves - for reproduction ex. kalanchoe

39. Insectivorous leaf - for absorption