WoodPlant body

Morphology of shoot

Introduction to Botany. Lecture 8

Alexey Shipunov

Minot State University

September 12th, 2010

Shipunov BIOL 154.8

WoodPlant body

Morphology of shoot

Monday test (5 points)

1 Differences between xylem and phloem (> 1)

2 Example of absorbtion tissue (> 0)3 What is protoderm?4 What is ataktostele?5 Components of bark (> 1)

Shipunov BIOL 154.8

WoodPlant body

Morphology of shoot

Monday test (5 points)

1 Differences between xylem and phloem (> 1)

2 Example of absorbtion tissue (> 0)

3 What is protoderm?4 What is ataktostele?5 Components of bark (> 1)

Shipunov BIOL 154.8

WoodPlant body

Morphology of shoot

Monday test (5 points)

1 Differences between xylem and phloem (> 1)2 Example of absorbtion tissue (> 0)

3 What is protoderm?

4 What is ataktostele?5 Components of bark (> 1)

Shipunov BIOL 154.8

WoodPlant body

Morphology of shoot

Monday test (5 points)

1 Differences between xylem and phloem (> 1)2 Example of absorbtion tissue (> 0)3 What is protoderm?

4 What is ataktostele?

5 Components of bark (> 1)

Shipunov BIOL 154.8

WoodPlant body

Morphology of shoot

Monday test (5 points)

1 Differences between xylem and phloem (> 1)2 Example of absorbtion tissue (> 0)3 What is protoderm?4 What is ataktostele?

5 Components of bark (> 1)

Shipunov BIOL 154.8

WoodPlant body

Morphology of shoot

Outline

1 Wood

2 Plant body

3 Morphology of shootComponents of shootBranchingArrangement of leaves

Shipunov BIOL 154.8

WoodPlant body

Morphology of shoot

Outline

1 Wood

2 Plant body

3 Morphology of shootComponents of shootBranchingArrangement of leaves

Shipunov BIOL 154.8

WoodPlant body

Morphology of shoot

Outline

1 Wood

2 Plant body

3 Morphology of shootComponents of shootBranchingArrangement of leaves

Shipunov BIOL 154.8

WoodPlant body

Morphology of shoot

Two taxonomic terms

“Gymnosperms” All seed plants except angiosperms =Spermatophyta − Magnoliopsida

“Dicots” All angiosperms except monocots =Magnoliopsida − Liliidae

Shipunov BIOL 154.8

WoodPlant body

Morphology of shoot

Conifer wood

Simpler structure, few cell typesSimple raysSometimes have resin ducts; resin secreted by epithelialcells

Shipunov BIOL 154.8

WoodPlant body

Morphology of shoot

Ginkgo (Ginkgo biloba) wood (not a conifer, butgymnosperm)

Shipunov BIOL 154.8

WoodPlant body

Morphology of shoot

Resin duct in pine wood ( c©BSA)

Shipunov BIOL 154.8

WoodPlant body

Morphology of shoot

Monocot “wood”

Most of monocots do not have lateral meristems andtherefore have no true woodPalms have only primary tissues; their trunk widens frombottom to topSome monocots (dragon trees) have anomaloussecondary growth

Shipunov BIOL 154.8

WoodPlant body

Morphology of shoot

Cross section of palm (Phoenix canariensis) trunk

Shipunov BIOL 154.8

WoodPlant body

Morphology of shoot

Dragon tree (Dracaena draco)

Shipunov BIOL 154.8

WoodPlant body

Morphology of shoot

Anomalous secondary growth in Bougainvillea(Bougainvillea spectabilis)

Shipunov BIOL 154.8

WoodPlant body

Morphology of shoot

Types of plant body

Thallous (flat, with non-differentiated organs)Shoot body (roots are absent)Bipolar body (root and shoot systems)

Shipunov BIOL 154.8

WoodPlant body

Morphology of shoot

Organs of bipolar plant

Leaf: flat lateral organ with restricted growthStem: axial aerial organ with continuous growthRoot: soil organ modified for absorptionFloral unit (FU): stable element of generative system

Shipunov BIOL 154.8

WoodPlant body

Morphology of shoot

Pseudo-organs

Hypocotyl : transition between stem and rootEpicotyl : first internode of plantBud : shoot “embryo”Fruit : temporary structure, ripe FUSeed : chimeric structure, has two or three genotypes

Shipunov BIOL 154.8

WoodPlant body

Morphology of shoot

Hypocotyl and epicotyl

Shipunov BIOL 154.8

WoodPlant body

Morphology of shoot

Organ systems

Vegetative shoot systemGenerative shoot systemRoot system

Shipunov BIOL 154.8

WoodPlant body

Morphology of shoot

Organs vs. organ systems

... Vegetativeshootsystem

Generativeshootsystem

Root system

Leaf + + −Stem + + ±Root ± ± +

FU − + ±

Shipunov BIOL 154.8

WoodPlant body

Morphology of shoot

Components of shootBranchingArrangement of leaves

Components of vegetative shoot system

1 Main and secondary shoots2 Terminal and axillary (lateral) buds3 Nodes and internodes4 Leaves

Shipunov BIOL 154.8

WoodPlant body

Morphology of shoot

Components of shootBranchingArrangement of leaves

Components of shoot

Shipunov BIOL 154.8

WoodPlant body

Morphology of shoot

Components of shootBranchingArrangement of leaves

Winter shoot

1 Vegetative, flower, and mixed buds2 Leaf and bud scars3 Leaf traces

Shipunov BIOL 154.8

WoodPlant body

Morphology of shoot

Components of shootBranchingArrangement of leaves

Winter shoot of maple (Acer platanoides)

Shipunov BIOL 154.8

WoodPlant body

Morphology of shoot

Components of shootBranchingArrangement of leaves

Types of branching

Monopodial: buds do not degrade, all shoots continue togrowSympodial: terminal buds degrade, the lateral shootclosest to terminal bud becomes terminal shoot

Shipunov BIOL 154.8

WoodPlant body

Morphology of shoot

Components of shootBranchingArrangement of leaves

Monopodial (left) and sympodial branching

Shipunov BIOL 154.8

WoodPlant body

Morphology of shoot

Components of shootBranchingArrangement of leaves

Arrangement of leaves

One leaf per node: spiral arrangementTwo leaves per node: opposite arrangement> 2 leaves per node: whorled arrangement

Shipunov BIOL 154.8

WoodPlant body

Morphology of shoot

Components of shootBranchingArrangement of leaves

Spiral arrangement

Multiple types of leaf spiral leaf arrangement mostly followFibonacci ruleFormulas of leaf arrangements is very similar to Finobaccifractions: 1

2 , 13 , 2

5 , 38 , 5

13 , et cetera*Numerator is number of spiral circulations, denominator isnumber of leaves

Shipunov BIOL 154.8

WoodPlant body

Morphology of shoot

Components of shootBranchingArrangement of leaves

Formulas of spiral arrangement

Shipunov BIOL 154.8

WoodPlant body

Morphology of shoot

Components of shootBranchingArrangement of leaves

Summary

Conifers have the simpler structure of woodMonocots usually do not have true wood, but some of themhave anomalous secondary growthIt is possible to divide plant body to different organs and/ororgan systemsBud, fruit and seed are pseudo-organsSympodial branching is evolutionary more advanced thanmonopodialSpiral arrangement of leaves follows Fibonacci rule

Shipunov BIOL 154.8

Appendix For Further Reading

For Further Reading

Th. L. Rost, M. G. Barbour, C. R. Stocking, T. M. Murphy.Plant Biology. 2nd edition.Thomson Brooks/Cole, 2006.Chapter 5.

Shipunov BIOL 154.8