Plant Anatomy: An Overview

Simpson, MG (2006). Plant Systematics

Eames and McDaniels (1953). Introduction to Plant Anatomy

IntroductionDefinition• Plant anatomy –the study of the internal

structure of various parts of the plant

Applications of plant anatomy• Taxonomic application

– e.g. problem plants

• Proper authentication of crude drug material– For safety and quality to be maintained– Morphology and anatomy of drug source is

published in British and English pharmacopoeias

Introduction

Applications of plant anatomy

• Avoids food adulterants and contaminants

Sambong (Blumea balsamifera L)

Mango (Mangifera indica L)

•FORENSIC APPLICATIONS Forensic botany refers to the use of plant materials to help solve crimes or resolve other legal problems. 

The first botanical testimony to be heard in a North American court concerned the analysis of the wood grain of the ladder used in the kidnapping of Charles Lindbergh Jr., and led to the conviction of Bruno Hauptmann for the crime in 1935.

Xylotomist Arthur Koehler of the United States Forest Service undertook a meticulous examination of the ladder and when the case finally came to trial four years later, offered the first botanical testimony ever to be heard and accepted in American courts.

LIVING ORGANISMS

Prokaryotes

Kingdom Monera

Eukaryotes

Unicell/simple multicellular organisms

Kingdom Protista

Multicellular organisms

Autotroph

Kingdom Plantae

Heterotroph

Saprophytes

Kingdom Fungi

Ingestion of other organisms

Kingdom Animalia

The five-kingdom system prevailed in biology for over 20 years.

LIVING ORGANISMS

•During the last three decades, systematists applying cladistic analysis, including the construction of cladograms based on molecular data, have been identifying problems with the five-kingdom system.

The Land Plants=Embryophyta (embryophytes)

• The first colonization of plants on land during the Silurian period, ca. 400 million years ago.

• Land Plants now dominate the earth.

GAMETOPHYTE(n)

Egg (n)

Sperm (n)

Zygote

(2n)

HAPLODIPLONTIC("Alternation ofGenerations")

SPOROPHYTE(2n)

Embryo(2n)

Spores(n)

lost by reduction and modificationin the Angiospermsand some Gnetales

Sporangium(2n)

Archegonium(n)

Antheridium(n)

fertilization

mitosismitosis

meiosis

mitosis

}

(Sperm non-flagellate in Conifers, Gnetales, and Angiosperms)

Sporocyte(2n)

produce

Marchantia (liverwort) Mnium (moss)

antheridium

antheridium

sperm cells

Marchantia (liverwort)

archegonium

egg cell

neck

“Bryophytes”

Liverworts

Hornworts

Mosses

•Vascular plants/ Tracheophytes- Xylem tissue, true roots, stems & leaves.

Fern and allies/ cryptogams: Spores but no seeds

1.Division Psilophyta (Psilotum or whisk fern)2.Division Lycophyta (club mosses)3.Division Sphenophyta (horsetails).4.Division Pterophyta (ferns).

Spermatophytes/ phanerogams: Seed Plants

•Gymnosperms--Naked Seeds

5. Division Cycadophyta (cycads)6. Division Ginkgophyta (maidenhair tree).7. Division Gnetophyta (mormon tea & Welwitschia).8. Division Coniferophyta (conifers)

•Angiosperms--Seeds Enclosed In A Fruit

9. Division Anthophyta (flowering plants)

Selaginella

Lycopodiella cernua

Equisetum

Psilotum

GENERAL STRUCTURE OF HIGHER PLANTS

Shoot Shoot systemsystem

leafleaf

bladebladeaxillary budaxillary bud

petiolepetiole

nodenode

vascular tissuevascular tissue

vascular tissuevascular tissue

shoot apical meristemshoot apical meristemterminal budterminal bud

internodeinternode

vascular tissuevascular tissue

root tiproot tip

Lateral rootsLateral roots

root caproot cap

root apical meristemroot apical meristem

RootRoot systemsystem

dermal tissuedermal tissueground tissueground tissuevascular tissuevascular tissue

Stelar types

eustele atactostele

Pericycle

Plant Tissues & Cell Types

Tissue:

= group of cells with common function or structure.

Three broad tissue types:

1) Dermal - outside layer(s)

2) Vascular - conduction

3) Ground - between dermal and vascular

Simple vs. Complex Tissue:

1 versus 2 or more cell types

Ground Tissue

Parenchyma: Gen. metabol.

1) Isodiametric to elongate

2) Primary cell wall

3) Living

Collenchyma: support

1) Elongate

2) Primary cell wall thick, uneven, rich in pectins

3) Living

Ground Tissue

Sclerenchyma

1) Secondary cell wall (+ primary)

2) Dead at maturity (usually)

Fibers

Elongate, sharply tapering

Ground Tissue

Sclerenchyma

1) Secondary cell wall (+ primary)

2) Dead at maturity (usually)

Sclereids

Isodiametric to irregular

3 recognized vegetative organs

• ROOT

• STEM

• LEAF

- Distinguished by the relative distribution of the vascular and ground tissues

ROOT vs Stem

ROOTS vs STEM

Leaves

Vascular Bundles of similar dimensions.

have a large central Vascular Bundle called a Midrib

DEVELOPMENT OF THE PLANT BODY

• Carpels and stamens– Contain the sporangia

• Sporangium– Contains the spores

– Chambers where male and female gametophytes develop

• Male gametophyte– Sperm-containing pollen grain

• Female gametophyte– Egg-containing structures called embryo sacs

– Embryo sac develop within the ovules

• Development of male gametophyte (Pollen)

• Development of female gametophyte (Embryo sac)

• Pollination

integument

funiculusmicropyle

POLLINATION

Embryogenesis

1. Transversie and Asymmetric division---Establishment of polarity

Terminal cell– embryoBalsal– suspensor

2. Organizaation of Tissue system

During the early stages of embryogenesis, cell divisiontakes place throughout the young sporophyte. Asthe embryo develops, however, the addition of newcells gradually becomes restricted to opposite ends ofthe axis, the apical meristems of future root and shoot

Seed GerminationSeed Dormancy