Chapter Three Leaves

1. Chapter Three Leaves Focus: physiological function, composition, lobed ,types and inner structure Difficulty: modification of leaf, difference of rachis and shoot

2. Part One Definition ,Physiological Function and Medicinal Value of Leaves ●一、Definition The leaf is the important vegetative organ of the plant. It is generally green flat body, have phototropism(向光性).

3. ● 二、Physiological function of the leaves 1.Photosynthesis 2.Respiration 3.Transpiration 4.Spit water function 5.Absorption 6.Preserving function 7.Reproductive function

4. 1.Photosynthesis

5. 2.Respiration

6. 3.Transpiration

7. 4.Spit water function

8. 5.Absorption

9. 6.Preserving function Fritillaria verticillata  Willd． var．thunberqii

10. 7.Reproductive function Begonia masoniana Bryophyllum pinnatum

11. ● 三、Medicinal value of the leaves

12. Folium Mori Folium ArtemisiaeArgyi Folium Eriobotryae Folium Isatidis

13. PartTwo一、Composition and Morphology of Leaves Fig. One composition of leaf 1. blade 2. Petiole 3. stipules 4.ocrea(托叶鞘)

14. Definition Complete leaf :has three parts called complete leaf. Incomplete leaf :Lack a part or two parts called incomplete leaf.

15. Composition of Leaves Blade: green , flat Petiole: Join the blade and stem ,and support the blade Stipules: Protect the immature blade

16. Petiole modification bulgy petiole Trans-petiole Leafy petiole Sheath-like petiole

17. Stipules Modification Ⅰ.CihuaiⅡ.QiancaoⅢ.YuxingcaoⅣ.Laliao Ⅴ.WandouⅥ.QiangweiⅦ.Baqia 1.Stipules 2. tendril 3. thorn 4. ocrea

18. 二、 Morphology of Leaves 1.The whole shape of the blade 2.The form of the leaf apex 3.The form of the leaf base 4.The form of the leaf margin

19. The whole shape of the blade

20. The form of the leaf apex

21. The form of the leaf base

22. The form of the leaf margin

23. Heterophylly: the same plant have different shaped leaves or the plants have different forms leaves in the defferent stages, this kind of phenomenon called the Heterophylly.

24. lobed of the blade : lobed parted divided

26. Veins: reticulate veins parallel veins

28. Texture of leaf blades herbaceous leaf Membranaceous leaf Succulent leaf Coriaceous leaf

29. Part Three Types of Leaves Simple Leaf and Compound Leaf Definition simple leaf（单叶）：Only grow a slice of blade on a petiole compound leaf (复叶)：Grow two or more blades on a petiole 1. ternately compound leaf ⒉ palmately compound leaf ⒊ pinnately compound leaf ⒋ unifoliate compound leaf

30. Types of compound leaf 1.ternately compound leaf 2.ternately compound leaf 3.palmately compound leaf 4. odd-pinnately compound leaf 5.even-pinnately compound leaf 6.bipinnate leaf 7.tripinnate leaf 8.unifoliate compound leaf

31. The type of compound leaf

32. ※The difference of rachis and shoot ①Terminal bud in shoot，but it isn’t in rachis. ②Bud in common petiole and leaflet base without bud. ③All leaflet of rachis in plane. ④Whole compound leaves fall off or leaflet fall off first , than rachis and common petiole fall off. but shoot not fall off.

34. 4 Phyllotaxy : alternate opposite whorled fascioled

35. Part Four Modification of Leaves 1.Bract 2.Scale leaf 3.Acicular leaf 4.Leaf tendril 5.Rhizomorphoid leaf 6.Insect-catching leaf

36. 1.Bract Bougainvillea spectabilis Houttuynia cordata

37. 1.Bract(spathe) Alocasiamacrorrhizos Pinelliaternata

38. 2. Scale leaf 3.Acicular leaf fritillaria Opuntiastricta(Haw.)Haw.var. dillenii

39. 4.Leaf tendril Pisum sativum Linn. Smilax china L.

40. 5.Rhizomorphoid leaf Salvinianatans Ceratophyllumdemersum

41. 6.Insect-catching leaf Dionaea muscipula

42. 6.Insect-catching leaf Droserapeltata Smith var. multisepala

43. 6.Insect-catching leaf Nepenthes mirabilis

44. Part Five Inner structure of the blade 一、Structure of the blade of the Dicotyledon ⑴Epidermis ⑵Mesophyll Palisade tissue Spongy tissue ⑶veins

45. ⑴Epidermis: upper epidermis , lower epidermis , multiple epidermis(2-3layers of cells) ★cutin : control the transpiration of the moisture , strengthen mechanical performance , prevent the germ from invading. ★hair : for distinguish the basis of the folium ★stoma : lower stoma more than upper stoma

46. ⑵Mesophyll Palisade tissue: it is neat to arrange , take the form of bar , having a large number of chloroplasts.

47. Spongy tissue: like sponge , the cell is irregular and arranging loosely , the interval is relatively big.

48. Definition Isobilateral leaf：No matter the form or internal structure are all similar in the upper and lower two sides of the leaf, call the Isobilateral leaf . (It is more seen in Gramineae . It can receive the light in the two sides . The mesophyll has no division which palisade tissue and sponge tissue or upper and lower sides have palisade tissue . ) For example , aiye

49. bifacial leaf：No matter external form or internal structure are all obviously different in the upper and lower two sides of the leaf, call the bifacial leaf or dorsi-ventral leaf . (the color of upper side :dark green , lower side : light green ) this bifacial leaf is common . For example , mint and tea.

50. ⑶veins: upper-xylem Lower-phloem The interior side of upper and lower epidermises has collenchyma and vascular bundle.