Lecture#1

INTRODUCTIONTOPLANTANATOMY

Introduction

Definition•  Plantanatomy–thestudyoftheinternalstructureofvariouspartsoftheplant

Applicationsofplantanatomy•  Taxonomicapplication

– e.g.problemplants

•  Properauthenticationofcrudedrugmaterial– Forsafetyandqualitytobemaintained– MorphologyandanatomyofdrugsourceispublishedinBritishandEnglishpharmacopoeias

Introduction

Applicationsofplantanatomy•  Avoidsfoodadulterantsandcontaminants

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.

WHAT IS A PLANT? A multicellular, eukaryotic, photosynthetic

autrotroph.

 With cell walls made mostly of cellulose

  Stored food in the form of starch

  Chlorophyll a directly involved in the conversion of light energy to chemical energy

  Chloroplasts contain chl b as accessory pigment

Kingdom Plantae

Vascular Non-Vascular

Bryophyta- Mosses

Hepatophyta-Liverworts

Anthocerophyta-Hornworts With seeds

(Phanerogams)

Without seeds

(Cryptogams)

Psilotophyta

Lycophyta

Sphenophyta

Pteridophyta

Naked seeds

Coniferophyta

Cycadophyta

Ginkgophyta

Gnetophyta

Covered seeds

Anthophyta

Monocots Eudicots

Kingdom Plantae Bryophytes (Mosses and allies)

 Small plants that lack true roots, stems and leaves

 They lack vascular tissue

 Water is necessary for the transfer of sperm prior to fertilization

 Gametophyte is dominant and nutritionally independent

Kingdom Plantae Bryophytes (Mosses and allies)  Sporophyte is permanently attached to

the gametophyte and dependent upon it for water and minerals

 Sex organs and sporangia are multicellular and have an outer layer of sterile cells

 Chlorophyll a and b and carotenoids are present in the plastids

 The first true land plants, a cuticle is present

 Influential in soil development by their participation in plant succession, assists in preventing soil erosion

Kingdom Plantae Bryophytes (Mosses and allies)

Kingdom Plantae

Vascular Non-Vascular

Bryophyta- Mosses

Hepatophyta-Liverworts

Anthocerophyta-Hornworts With seeds

(Phanerogams)

Without seeds

(Cryptogams)

Psilophyta

Lycophyta

Sphenophyta

Pterophyta

Naked seeds

Coniferophyta

Cycadophyta

Ginkgophyta

Gnetophyta

Covered seeds

Anthophyta

Monocots Eudicots

Division Psilophyta (whisk fern)

Division Psilophyta (whisk fern)

 Sporophyte have scalelike leaves (enations)

 No roots

 Dichotomously branched

 Terminal sporangia (synangium, plural synangia)

Division Psilophyta (whisk fern)

 Homosporous – with only one type of meiospore

 Water is necessary for transfer of sperm previous to fertilization

 Both sporophyte and gametophyte are nutritionally independent

Division Psilophyta (whisk fern)  Sex organs and sporangia are multicellular

and have an outer layer of sterile cells

• Genera: Psilotum, Tmesipteris

Division Lycophyta (club mosses)

Division Lycophyta (club mosses)

•  Sporophytes may be homosporous or heterosporous (two kinds of meiospores)

• Have roots, stems and small leaves

•  Single sporangia are borne on the upper surface of leaves (sporophylls) which are arranged in the form of a cone or strobilus

Division Lycophyta (club mosses)

• Water is necessary for fertilization to occur

•  The sporophyte is dominant over gametophyte

•  Both sporophyte and gametophyte are nutritionally independent

Division Lycophyta (club mosses) •  Sex organs and sporangia are multicellular

and have an outer layer of sterile cells

• Genera: Lycopodium, Selaginella

Division Sphenophyta (Horsetails)

Division Sphenophyta (Horsetails)

 Sporophytes have roots, stems, and small leaves

 The leaves and branches are whorled

 The stem is hollow, jointed and contains silica

Division Sphenophyta (Horsetails)

 Groups of sporangia are borne on stalked, umbrella-like structures, which are grouped to form strobili

 Sporophyte is the dominant phase

 The gametophyte is small and both are nutritionally independent

Division Sphenophyta (Horsetails)

 Elaters are present on meiospores

 Water is necessary for sperm transfer

 Sex organs and sporangia are multicellular and have an outer layer of sterile cells

 Genus : Equisetum

Division Pterophyta (Ferns)

Division Pterophyta (Ferns)

 The dominant sporophyte usually have roots, stems and large leaves

 Leaves are typically compound and uncoil as they develop (circinate vernation)

 Roots are typically adventitious from a horizontal rhizome

 Most are homosporous

Division Pterophyta (Ferns)

 The gametophyte is nutritionally independent, like the larger sporophyte

 Water is necessary for fertilization by swimming sperm

 Sex organs and sporangia are multicellular and have an outer layer of sterile cells

Division Pterophyta (Ferns)

 Sporangia are borne on the lower surface of leaves or sporophyll

 Genera: Polypodium, Pteris, Adiantum

Kingdom Plantae

Vascular Non-Vascular

Bryophyta- Mosses

Hepatophyta-Liverworts

Anthocerophyta-Hornworts With seeds

(Phanerogams)

Without seeds

(Cryptogams)

Psilotophyta

Lycophyta

Sphenophyta

Pteridophyta

Naked seeds

Coniferophyta

Cycadophyta

Ginkgophyta

Gnetophyta

Covered seeds

Anthophyta

Monocots Eudicots

 has fanlike leaves that turn gold before they fall off in the autumn.

Phylum Ginkgophyta consists of only a single extant species, Ginkgo biloba.

Phylum Cycadophyta (Cycads)  superficiallyresemblepalms. plantsareheterosporous Genus:Cycas,Zamia

Phylum Gnetophyta

 Traits are intermediate between gymnosperms and angiosperms

 With vessels in xylem

 The ovules are surrounded by 2 integuments

Phylum Gnetophyta

 Pollen-producing structures superficially resemble stamens

 Seeds naked; fruits absent

 Consists of three very different genera.

Phylum Gnetophyta

• Weltwitschia, from deserts in southwestern Africa, have straplike leaves.

Phylum Gnetophyta • Gnetum species are tropical trees or vines

(mainly climbing lianas), the leaves very much like dicots

Phylum Gnetophyta

Ephedra (Mormon tea), shrub of the American deserts with whorls of small deciduous leaves)

– .

Division Coniferophyta

Division Coniferophyta

 Have roots, stems and large leaves

 Leaves are usually evergreen needles or scales

 Heterosporous (produce 2 kinds of meiospores)

 Gametophytes are nutritionally dependent on the sporophyte

Division Coniferophyta

 Wind pollinated; pollen tubes are formed

 Genera: Pinus, Abies (Firs), Tsuga

Division Coniferophyta  Conifer sporophyte

 All species of pines are trees

 Conifer wood has no vessels

 Typically with resin ducts

 With sieve cells and albuminous cells in the phloem

Division Coniferophyta

Division Coniferophyta

Ovulate (Seed) Cones  Develop at tips of young branches

 Two ovules, each enclosing a single megasporangium, develops on the upper surface of an ovuliferous scales

 An ovule consists of : outer integument, nucellar tissue and the female gametophyte; at one end are several archegonia

Division Coniferophyta

 Fertilizationisachievedbyunionofspermwithanegg;normallyonlyoneembryosurvive

 Thematureembryoconsistsofseveralcotyledons,radicle,epicotylandhypocotyls

DivisionAnthophyta(Floweringplants)

 Dominant sporophytes have roots, stems and leaves

 Sporangia borne on stamens and carpels

 Seeds develop from ovules which are enclosed by carpels

DivisionAnthophyta(Floweringplants)

 The gametophytes are very reduced and dependent upon the sporophyte

 Female gametophyte retained within the sporangium

 Wind or insect pollinated

 Double fertilization occurs

 Eudicots- With 2 cotyledons, flower parts in multiples of 4s or 5s, leaves are net-veined, cambium is usually present

 Monocots- With one cotyledon, flower parts in multiples of 3s; the leaves are parallel-veined, a cambium is usually lacking

• Whilemostangiospermsbelongtoeitherthemonocots(65,000species)oreudicots(165,000species)severalothercladesbranchedoffbeforethese.

THEEND