1. Chapter 4 Lessons 3Herbaceous stemsCharacterisitcs:a.Live only one growing seasonb. smaller than a wood stemc. Important to man as cropsd. No annual rings because live onlyone season

2. Dicot herbaceous stems:Xylem and phloem cells formfibrovascular bundles arranged inrings around the pith 3. Dicot herbaceous stems:Xylem and phloem cells form fibrovascular bundles arranged in ringsaround the pithXylem is in the center of the ring and thephloem is on the outside 4. Monocot herbaceous stemsVascular bundles are scatteredHas a rind or outer covering of thestemUsually has no cambium tissue 5. Chapter 4 Lesson 4Vegetative Reproduction asexualreproduction from the stem, leaf orroot instead of from seeds. The Encyclopedia. 2000 6. Vegetative Reproduction asexual reproduction from the stem, leaf or rootinstead of from seeds Also called vegetative propagationThe Encyclopedia. 2000 7. In asexual reproduction:Offspring are genetically identical toparentExample is a strawberry thatproduces runners 8. Adventitious roots roots that growfrom unexpected regions of the plantlike the stem, branch or leaf 9. Types of Vegetative propagation1.Cuttings piece of stem or rootplaced in medium (water or soil) androots will grow to make a new plant 10. Types of Vegetative propagation1. Cuttings2.Layering when a portion of a stem grows roots while still attached to the parent plant, it will then detach.Ex. Honeysuckle 11. Types of Vegetative propagation1. Cuttings2. Layering3.Grafting process of transplanting livingtissue from one plant to another.Ex. grapes 12. Types of Vegetative propagation1. Cuttings2. Layering3.GraftingAdvantages of grafting: saves time get mature plantalmost immediately You get the best attributes ofboth plants 13. Types of Vegetative propagation1. Cuttings2. Layering3.GraftingTerms: Scion part that is grafted in Stock where the scion isplaced 14. Types of Vegetative propagation1. Cuttings2. Layering3.Grafting Method is used for McIntosh applesand for grapes It is mentioned in the BibleIf some of the branches have been broken off, and you, though awild olive shoot, have been grafted in among the others and nowshare in the nourishing sap from the olive root, 18 do not consideryourself to be superior to those other branches. If you do, considerthis: You do not support the root, but the root supports you. 19 Youwill say then, "Branches were broken off so that I could be graftedin." 20 Granted. But they were broken off because of unbelief, andyou stand by faith. Do not be arrogant, but tremble. 21 For if God didnot spare the natural branches, he will not spare you either. 15. Types of Vegetative propagation1. Cuttings2. Layering3.Grafting4. Budding a type of grafting where the bud is used as the scion.Typical with apple trees.Shield-budding the mango. On the left, a bud properlyinserted; next, an inserted bud wrapped with a stripof waxed cloth; above the knife-point, a properlycut bud; and on the right, budwood of desirable character. 16. Types of Vegetative propagation1. Cuttings2. Layering3.Grafting4. Budding5.Tissue culturing Relatively new process A cell is placed in a petridish with the propermedium, given hormones, and it willdevelop into a new plant 17. Important hormones in plants1.AuxinFirst group discoveredImportant to root and shoot growth intropismscauses cells in one area to grow longer 18. Important hormones in plants1.AuxinSecreted in shoot but mainly affectthe rootUsed in root starter when plantingnew plants. 19. Important hormones in plants1.Auxin2. Cytokinins promotes cell divisionsecreted mostly in the roots andaffects the shootAuxins and cytokinins work togetherto promote growth 20. Important hormones in plants1. Auxins2. Cytokinins3.Gibberellins regulate the proper amount ofgrowth If you reduce gibberellins you endup with dwarf plants. 21. Important hormones in plants1. Auxins2. Cytokinins3.Gibberellins4. Abscisic acidMajor role in bud and seedgermination dormancy when plantstressed due to unfavorableconditionsInhibitory affecton gibberellins 22. Important hormones in plants1. Auxins2. Cytokinins3.Gibberellins4. Abscisic acid5. Ethylene responsible for leaf abscission and fruit ripening. 23. Special stems.1. Bulbs ex. Onion; designed forfood storage2. Rhizomes thick stems that growhorizontally under ground Store food Form of vegetative propagation Ex. Iris, grasses 24. Special stems1. Bulbs2, Rhizomes3. Stolons or runners stem grows quickly along the surface of the ground (above ground) to produce new plants where a node touches the soilEx. strawberry 25. Special stems1. Bulbs2. Rhizomes3. Stolons or runners4.Tendrils a stem where hormonesstimulate the cell on the opposite sideto grow longer where the stemtouches an object causing the stem towind around the objectEx. beans 26. Special stems1. Bulbs2. Rhizomes3. Stolons or runners4. Tendrils5. Stem Tubers Modified portion of stem to store food Also form of asexual reproduction Ex. Potatoes Also there are root tubers ex.yams 27. Special stems1. Bulbs2. Rhizomes3. Stolons or runners4. Tendrils5. Stem Tubers6. Thorns Modified portion of stem for protection Ex. Honey locust Dont confuse with spines which are modified leaves 28. RootsTwo types of roots are:A. Fibrous rootsBranching main central rootMonocots have themEx. grasses 29. RootsTwo types of roots are:A.Fibrous rootsB.Tap roots Have an enlarged main root Dicots have them Ex. carrots, dandelions 30. RootsParts of a root cross section:1. Epidermis outside layer that protects the root from water loss 31. RootsParts of a root cross section:1.EpidermisRoot hairs are projections of theepidermis that increase the surfacearea of the root for better waterabsorption. 32. RootsParts of a root cross section:1.Epidermis Root hairs2. Cortex the next layer in from the epidermis and is where food is stored. 33. RootsParts of a root cross section:1.Epidermis Root hairs2.Cortex3. Stele central cylinder of the rootthat contains the xylem and phloem. 34. RootsThree regions of primary root growth:a. Meristemic region region closest to the end where cell division takes place 35. RootsThree regions of primary root growth:a.Meristemic regiona. Region of elongation just abovethe meristemic region and is where cells will increase in length pushing the root down 36. RootsThree regions of primary root growtha. Meristemic regionb. Region of elongationc. Maturation region where cellsbecome specialized and incorporated inthe stele/cortex. 37. RootsRoot Cap is at the end of the root protecting and covering it is several cell layersthick Secretes slime to reduce friction 38. RootsSecondary Growth or lateral growth: Takes place in the cambium tissue Addition of new xylem and phloemby vascularcambium cells 39. RootsSpecialized root functions:1. Prop roots adventitious roots that arisesfrom the stem add support Ex. corn 40. RootsSpecialized root functions:1. Prop roots2. Bald cypress knees Stick above the water Presumed to provideoxygen to other roots butno scientific evidence Give added support?? Purpose unknown 41. Roots Specialized root functions: 1. Prop roots2. Bald cypress knees3. Desert plant roots secrete chemical inhibitors to keep other plants from growing nearby.