藥用植物學(xué)教案葉的形態(tài)與結(jié)構(gòu)

1、Chapter 6 The LeafFunctionsForm and ModificationsStructures1FunctionsPhotosynthesisRespirationTranspirationStorage2FormThree parts:Leaf bladePetioleStipuleComplete, Incomplete3Leaf bladePetioleStipule4Leaf TypesSimple leafthe blade is all in one piece, though it may be lobed, toothed, etc.Compound l

2、eafthe blade is divided all the way to the midrib (rachis) into two or more pieces (leaflets).Pinnate, Palmate, Unifoliate5Simple Leaf6Compound Leaf789The Difference between a Stem with Simple Leaves and a Compound Leaf 1. The tip of the rachis never has a terminal bud.2. Leaflets never bear buds in

3、 their axils. 3. Leaflets all lie in the same plane.4. The rachis falls off with leaflets.10The Leaf MorphologyLeaf shapesLeaf marginsLeaf apicesLeaf basesLeaf lobesLeaf venationLeaf texture11Leaf shapes12Leaf shapes1314151617181920212223Leaf margins24Leaf apices25262728293031Leaf bases32Leaf lobes3

4、3The Difference between Leaflets and LobesPetiolules: exist or notRachis: exist or notArrangement: symmetric or notShapes and Size: similar or not34Leaf venation35The PhyllotaxisGeneral rule: mosaic arrangement互生 Spiral (Alternative)對生 Opposite輪生 Whorled簇生 Fascicled3637The Modified Leaves苞片 Bracts鱗片

5、 Scales葉刺 Spines (Thorns, Prickles)葉卷須 Tendrils葉狀柄 Phyllodes捕蟲葉 Insect traps異型葉性 Heterophylly38苞片 Bracts39苞片 Bracts40鱗片 Scales41鱗片 Scales42葉刺 Spines43葉卷須 Tendrils44葉狀柄 Phyllodes45捕蟲葉 Insect traps46捕蟲葉 Insect traps47葉的內(nèi)部結(jié)構(gòu)表皮 Epidermis葉肉組織 Mesophyll維管組織 Vascular tissues兩種類型: 兩面葉 Bifacial leaves: 水平伸展等面葉 Isolateral leaves: 垂直伸展48表皮 Epidermis組成：扁平、板塊狀的表皮細(xì)胞；保衛(wèi)細(xì)胞；表皮毛氣孔的分布：兩面葉：單側(cè)性分布 等面葉：對稱性分布 49薰衣草葉 Lavender Leaf50Lavender-leaf51花生葉 Pea Leaf Stoma, Vicea sp. (SEM x3,520). 52Cross-Section Through a StomataSubsidiary cellGuard cellSubstamatal chamber53葉肉組織 Mesophyll兩面葉：柵欄組織 Palisade mesophyll海綿組織 Spo