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

2. Definition ,Physiological Function and Medicinal Value of Leaves
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 Artemisiae Argyi
Folium Mori
Folium Artemisiae Argyi
Folium Eriobotryae
Folium Isatidis

13. Part Two 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 Leafy petiole Sheath-like petiole
Trans-petiole
Leafy petiole
Sheath-like petiole

17. Stipules Modification
Ⅰ.Cihuai Ⅱ.Qiancao Ⅲ.Yuxingcao Ⅳ.Laliao
Ⅴ.Wandou Ⅵ.Qiangwei Ⅶ.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
Coriaceous leaf
Succulent 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. Alocasia macrorrhizos
1.Bract(spathe)
Alocasia macrorrhizos
Pinellia ternata

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

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

40. 5.Rhizomorphoid leaf
Salvinia natans
Ceratophyllum demersum

41. 6.Insect-catching leaf
Dionaea muscipula

42. 6.Insect-catching leaf
Drosera peltata 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.

51. 3 2 4 1 6 7 8 9 5 Transverse section of leaf of Herba Menthae
1.non-glandular hair 2.upper epidermis 3.palisade tissue
4.spongy tissue 5.lower epidermis 6.stoma
7.Xylem 8.phloem 9.collenchyma

53. 二、Structure of the Blade of the Monocotyledon
△Character:
bulliform cell and vascular bundle sheath.

54. 1、upper epidermis 2、stoma 3、epidermis hair
Structure of the blade
of Monocotyledon
1、upper epidermis 2、stoma 3、epidermis hair
4、parenchyma 5、vascular bundle in midrib 6、bulliform cell
7、sclerenchyma 8、lower epidermis 9、cutin
10、 vascular bundle in lateral veins

56. 三、Structure of the Blade of the Gymnosperm
hypodermis , shrring(chloroplast ditribute along shirring and enlarge area of photosynthesis) , plunging stoma , resinic way.

57. Structure of the blade of Gymnosperm
1、lower epidermis
2、mesophyll
3、upper epidermis
4、endodermis
5、cutin
6、vascular bundle
7、stoma
8、resin canal
9、parenchyma
10、the room under stoma

59. Review Questions
一.Definition
Complete leaf , incomplete leaf , heterophylly, simple leaf, compound leaf , unifoliate compound leaf , bifacial leaf and isobilateral leaf
二.simple answer
1.what is the difference of the rachis and small shoot?
2.what is the function of leaves?
3.How about the inner structure of leaves of Dicotyledoneae?