1) Morphology is the study of the external features, arrangement, and relationships of plant organs. Roots grow underground and absorb water and minerals, anchoring the plant. Stems grow above ground and transport nutrients between roots and leaves. 2) Roots have various modifications including storage roots, prop roots, stilt roots, climbing roots, and parasitic roots. Stems also have modifications underground like bulbs, corms, rhizomes, and above ground like runners, stolons, and suckers. 3) Vegetative plant organs include roots, stems, and leaves. Roots have different root systems and serve functions of anchoring, absorption, and storage. Stems support leaves and

1. Root & stEMmoRPHOLOGY(including MODIFICATIONS)Made by-V.V.S.S.PREETISr. MEDICON -1Roll no- 33

2. WHAT IS MORPHOLOGY?Morphology is the study of –External features of plants,Arrangement,RelationshipOf organs.The underground part of flowering plant is the root system while the portion above the ground forms the shoot system.Plant has vegetative and reproductive organs

3. Vegetative OrgansRootsStemsLeaves

4. THE ROOTLOCATION- grows undergroundTYPES OF ROOTS-1) Primary- formed directly from axis of embryo plant.2) Lateral- arises from primary.

5. TYPES OF ROOT SYSTEMSG

6. Function of rootsAnchor the plantAbsorb water and minerals from soilStorage

7. Fig. 38.21

8. STORAGE ROOTSSWOLLEN ADVENTIOUS ROOTSSWOLLEN TAP rootsFUSIFORM-eg:raddishNAPIFORM-eg:beetrootCONICAL -eg;carrotFASICULATED-eg asparagus

9. NODULATED -eg: ginger

10. MONILIFORM-eg: grasses

11. Sweet potatoPROP ROOTSIN BANYAN TREE,Branches give off roots that grow into the soil & support the branches

12. STILT ROOTS IN SCREWPINE short roots grow obliquely downward from near base of stem

13. CLIMBING ROOTS IN climbers like PEPPER & BETEL NUT,adventitious roots are formed at nodes which help in climbing.

14. EPIPHYTIC ROOTSIN VANDA,Base of tissue grows spongy tissue termed velamen that absorbs moisture from the air

15. CONTRAC TILE ROOTSIN COLACASIA,They posses roots that contract so underground roots are kept at proper levels.

16. FLOATING ROOTSIN JUSSIAEAroots are white, spongy filled with air.Help plants to float

17. BREATHING ROOTSIN AVICENNIA,Roots grow into vertical branches that have openings called Pneumetaphores for root aeration.

18. REORODUCTIVE ROOTSExposed roots of MURRAYAHave adventitious buds which grow into new plants.

19. PARASITIC ROOTSIN CUSCUTAHaustoriaPenetrate into host stem & enter vascular bundles which absorb materials.

20. ASSIMILATORY ROOTSIN TRAPA,Adventious roots with chlorophyllous tissue capable of photosynthesis.

21. FOLIAR ROOTSINBRYOPHYLLUMRoots arise from lamina, petiole,veins

22. TUBERCULAR ROOTSIN SWEET POTATOLateral roots are swollen &Without definite shape.

23. THE STEMThe stem grows erect& lifts the leaves , exposing them to sunlight.it also conducts materials from roots to leaves. Based on nature of stem,plants are divided into herbs,shrubs & trees

24. Function of Stemssupport leaves to maximize light absorptionpart of conduit for transport of water, minerals, and organic solutesstorage

25. UNDERGROUND MODIFICATIONS OF STEMBULBDry scale leaves,Tunicated,Stem is small reduced & disk shaped.RHIZOMESGrows horizontally,Elongated.stem nature is evident from CATAPHYLLS.

26. AMORPHOPHYLLUSPOTATOSTEM TUBERIn potato,An aerial branch grows downward &stores food CORMIn amorphophyllusStem is massive,swollen,Held in position by contractile roots

27. SUBARIEL MODIFICATIONS FOR VEGETATIVE PROPOGATIONRUNNERIn StrawberryAxillary buds from lowest leaves give rise to modified branches.STOLONThey grow upwardsLike ordinary branches & arch down to meet soil.STOLON

28. EICHHORNIAMENTHA arvensisSUCKERIn menthaIt goes up & forms a daughter plant after striking rootOFFSETIt is shorter & thickerFound in aquatic plantsSUCKEROFFSET

29. ARIEL MODIFICATIONS OF STEMTENDRILSIN grapesAxillary bud is modified into tendrils.CLADOPHYLL /PHYLLOCLADEThe entire shoot is flattend & leaf like.