plant classification, function, and structure. introduction plants are complex organisms that...

Plant Classification, Plant Classification, Function, and StructureFunction, and Structure

IntroductionIntroduction

Plants are complex organisms that consist of tissues and cells Plants consist of leaves, stems, roots, and flowers Understanding plant growth and the function of plants is very

important in horticulture Horticulturists apply their knowledge of plant anatomy of the

different plant organs to promote growth and high quality crops

ObjectivesObjectives

1. Explain why it is important to classify plants Explain different ways plants are classified according to

their taxonomy, and use scientific naming• Explain the hierarchal classification system• Use a dicotymous key to classify organisms

2. Describe the differences among annuals, biennials, and perennials

3. Explain the processes of photosynthesis and respiration

Objectives (Learning Goals)Objectives (Learning Goals)

4. Identify and describe the functions of the vegetative plant partsa. Leaves

Identify and describe the parts the functions of the internal and external leaf structuresDiscuss the differences between simple and compound leaves, and identify types of compound leaves and their arrangement on a stem

b. StemsIdentify and describe the parts and functions functions of the internal and external stem structures

c. RootsIdentify and describe the parts and functions of the internal and external root structures

Describe the differences between taproot, fibrous, and adventitious root systems

5. Identify and describe the parts and functions of reproductive plant partsExplain the difference between complete and incomplete flowersIdentify types of flower inflorescences

6. Explain the economic importance of all plant parts7. Describe the structural differences between monocots

and dicots

Plant ClassificationPlant Classification

1. Explain why it is important to classify plants2. Explain different ways plants are classified

• Explain and use Scientific Plant Classification and Naming

• Explain the hierarchal classification system• Use a dicotymous key

3. Describe the differences among annuals, biennials, and perennials

Why Classify Organisms?Why Classify Organisms?

Classification systems improve:Classification systems improve: our ability to explain relationships among thingsour ability to explain relationships among things aid our memoryaid our memory aid our predictionaid our prediction provide unique, universally used names for provide unique, universally used names for

organismsorganisms

Classifying PlantsClassifying Plants

Scientists use the similarities of plants to Scientists use the similarities of plants to classify them into groups.classify them into groups.

There are different classification systems There are different classification systems based onbased on Stem TypeStem Type Foliage RetentionFoliage Retention Life Cycle Life Cycle UseUse Scientific classificationScientific classification

Stem Type ClassificationStem Type Classification Herbaceous Plants – have Herbaceous Plants – have

stems that are soft and not stems that are soft and not woody (herbs, vines, woody (herbs, vines, turfgrasses) that die back to turfgrasses) that die back to the ground each yearthe ground each year

Woody Plants- shrubs, trees, Woody Plants- shrubs, trees, or certain vines which or certain vines which produce wood and have buds produce wood and have buds surviving above ground over surviving above ground over winterwinter

Foliage RetentionFoliage Retention Deciduous Plants- Deciduous Plants-

leafless during portion of leafless during portion of the year (winter)the year (winter)

Evergreen- keep leaves Evergreen- keep leaves year roundyear round

Narrow leaf (needle like Narrow leaf (needle like leaves) evergreensleaves) evergreens

Broadleaf (flattened leaf Broadleaf (flattened leaf blade) evergreensblade) evergreens

Life Cycle – Life Cycle – Vegetative phase: part of life when a plant seed germinates Vegetative phase: part of life when a plant seed germinates

and grows producing leaves, stems and roots.and grows producing leaves, stems and roots. reproductive phase: plant flowers and produces fruit reproductive phase: plant flowers and produces fruit senescence or dormancy phase: inactive or slow plant senescence or dormancy phase: inactive or slow plant

growthgrowth Annuals – complete life cycle in less than one yearAnnuals – complete life cycle in less than one year Biennials – complete their life cycle in two yearsBiennials – complete their life cycle in two years Perennials – herbaceous or woody plants that grow indefinitely Perennials – herbaceous or woody plants that grow indefinitely

from year to yearfrom year to year

Annuals- flowering, then Annuals- flowering, then production of seed is a sign production of seed is a sign of deathof death Dead-heading: the removal of Dead-heading: the removal of

flowers and seeds to continue flowers and seeds to continue life and bloom for longer life and bloom for longer periods of timeperiods of time

Annuals are often divided Annuals are often divided into groups based on what into groups based on what season or climate is best for season or climate is best for growthgrowth

BiennialsBiennials During first season of During first season of

growth the plants grow growth the plants grow vegetatively then vegetatively then become dormant in become dormant in winterwinter

The following spring the The following spring the plants produce flowers plants produce flowers and fruit then die.and fruit then die.

Perennials: plants that Perennials: plants that live for more than two live for more than two seasonsseasons Above ground portions Above ground portions

of perennials generally of perennials generally die in winter but grow die in winter but grow new shoots and leaves new shoots and leaves the following spring the following spring from the below-ground from the below-ground portions of the plantportions of the plant

Can be deciduous or Can be deciduous or evergreenevergreen

HardinessHardiness Tender plant: unable to Tender plant: unable to

survive extreme climate survive extreme climate and temperatureand temperature

Hardy plant: able to Hardy plant: able to withstand colder withstand colder temperaturestemperatures

UseUse EdibleEdible OrnamentalOrnamental MedicinalMedicinal Back in the day:Back in the day:

Poisonous Poisonous safesafe

Scientific NamingScientific Naming Avoid confusion concerning the names of Avoid confusion concerning the names of

plants. plants. Scientific names of plants are expressed in Scientific names of plants are expressed in

Latin because it is a international language and Latin because it is a international language and was used by early scholars to express plant was used by early scholars to express plant namesnames

Scientific ClassificationScientific Classification Based on morphology of plants (form and structure)Based on morphology of plants (form and structure) Botanical Nomenclature: scientific classification of plantsBotanical Nomenclature: scientific classification of plants

Includes Genus, Species, Variety, CultivarIncludes Genus, Species, Variety, Cultivar

Scientific Name: Scientific Name: written in Latinwritten in Latin First letter is always capitalized and the species is lower caseFirst letter is always capitalized and the species is lower case Plants in same genus have similar characteristicsPlants in same genus have similar characteristics Variety or cultivar: given to plants of the same species that have a Variety or cultivar: given to plants of the same species that have a

sufficiently different appearancesufficiently different appearance

Latin names of plants are Latin names of plants are italicized:italicized:

Because it is conventional to italicize words Because it is conventional to italicize words and phrases that are expressed in a different and phrases that are expressed in a different language.language.

Example - The most commonly known Example - The most commonly known cultivars of cultivars of Acer rubrum Acer rubrum ( red maple) are “Red ( red maple) are “Red Sunset” and “Autumn Flame,” which are the Sunset” and “Autumn Flame,” which are the most reliable for brilliant reds and a long-most reliable for brilliant reds and a long-lasting display of foliage.lasting display of foliage.

The generic name of the The generic name of the plant is:plant is:

Placed first and begins with a large letter.Placed first and begins with a large letter.

Examples: Examples: AcerAcer-(maple),-(maple), Papaver Papaver-(poppy),-(poppy), PinusPinus-(pine)-(pine)

When classifying plants, it is important to first When classifying plants, it is important to first understand that the more they are categorized understand that the more they are categorized the more specific the plant categories are. the more specific the plant categories are. Classification begins with Kingdom and Classification begins with Kingdom and continues with Phylum, Classes, Orders, continues with Phylum, Classes, Orders, Families, Genera, and Species. Each of these Families, Genera, and Species. Each of these can be further subdivided.can be further subdivided.

A genus can be defined as:A genus can be defined as: A group of plants that have more in common A group of plants that have more in common

with each other than they have with the with each other than they have with the members of any other genus.members of any other genus.

A species can be defined as:A species can be defined as: A group of plants that are alike in almost every A group of plants that are alike in almost every

feature and consistently produce like plants.feature and consistently produce like plants. Example - Example - Betus luteaBetus lutea is yellow birch ( is yellow birch (lutealutea

means “yellow”)means “yellow”)

TAXONOMISTTAXONOMIST A person who identifies and classifies plants!A person who identifies and classifies plants!

Kingdom PlantaeKingdom Plantae

Plants dominate the land and many bodies of Plants dominate the land and many bodies of water. Plants exhibit tremendous diversity. water. Plants exhibit tremendous diversity. Some plants are less than .04 inches in width, Some plants are less than .04 inches in width, and some plants grow to more than 328 ft in and some plants grow to more than 328 ft in height. height.

All organisms in this kingdom are All organisms in this kingdom are multicellular and most are photosynthetic and multicellular and most are photosynthetic and live on land. live on land.

The first true plant is thought to have been The first true plant is thought to have been similar to a green alga, with adaptations that similar to a green alga, with adaptations that enabled it to survive the dry conditions of enabled it to survive the dry conditions of land. land.

From that algal ancestor, a wide variety of From that algal ancestor, a wide variety of plants have evolved.plants have evolved.

Phylum BryophytaPhylum Bryophyta

Know as mosses:Know as mosses: More than 10,000 speciesMore than 10,000 species No vascular tissueNo vascular tissue Seedless, reproduce with Seedless, reproduce with

sporesspores SphagnumSphagnum moss is a genus moss is a genus

of moss that is a major of moss that is a major component of peat bogs component of peat bogs and has a high water and has a high water holding ability, making holding ability, making very useful to the world of very useful to the world of horticulturehorticulture

Phylum Hepatophyta Phylum Hepatophyta

Know as liverwortsKnow as liverworts 6,500 species6,500 species Unusual looking plants Unusual looking plants

that grow in moist shady that grow in moist shady areasareas

Non-vascularNon-vascular

Phylum AnthoceroophytaPhylum Anthoceroophyta

Known as HornwartsKnown as Hornwarts 100 species100 species NonvascularNonvascular Resemble liverwartsResemble liverwarts They share an unusual They share an unusual

characteristic with algae; characteristic with algae; each cell usually has a each cell usually has a single large chloroplast single large chloroplast rather than numerous rather than numerous small onessmall ones

Phylum PsilotophytaPhylum Psilotophyta

Known as whisk fernsKnown as whisk ferns 10-13 species10-13 species Vascular, seedlessVascular, seedless Not actually ferns, have Not actually ferns, have

no leaves or rootsno leaves or roots Epiphytes- grow on other Epiphytes- grow on other

plants but not considered plants but not considered parasitesparasites

Phylum Lycophyta Phylum Lycophyta

Club MossesClub Mosses 1,000 species1,000 species Vascular seedlessVascular seedless Look like miniature pine Look like miniature pine

treestrees Bear spores and have Bear spores and have

rootsroots Many are endangered Many are endangered

speciesspecies

Phylum SphenophytaPhylum Sphenophyta

HorsetailsHorsetails 15 species15 species Vascular seedlessVascular seedless Jointed stemsJointed stems Outer cells contain silica, Outer cells contain silica,

the major component of the major component of sandsand

Often used by american Often used by american pioneers to scour pots pioneers to scour pots and pansand pans

Phylum PterophytaPhylum Pterophyta

FernsFerns 12,000 species12,000 species Vascular, seedlessVascular, seedless Beautiful and feathery Beautiful and feathery

leavesleaves Most have an Most have an

underground stemunderground stem Most produce spores on Most produce spores on

the underside of their the underside of their leavesleaves

Phylum CycadophytaPhylum Cycadophyta

CycadsCycads Gymnosperms Gymnosperms Vascular with seedsVascular with seeds 100 species100 species Most lived in age of Most lived in age of

dinosaursdinosaurs Now mostly ornamentalNow mostly ornamental Look fernlikeLook fernlike

Phylum GinkgophytaPhylum Ginkgophyta

GinkgoGinkgo Gymnosperms Gymnosperms Vascular with seedsVascular with seeds 1 species1 species Also flourished in age of Also flourished in age of

dinosaursdinosaurs Ginkgo bilobaGinkgo biloba is only is only

remaining species native remaining species native to Chinato China

Phylum ConiferophytaPhylum Coniferophyta

ConifersConifers 550 species550 species GymnospermsGymnosperms Vascular with seedsVascular with seeds Important sources of Important sources of

wood, paper, turpentine, wood, paper, turpentine, resin, ornamental plants resin, ornamental plants (used in horticulture)(used in horticulture)

Gin flavored with juniper Gin flavored with juniper seedsseeds

Phylum GnetophytaPhylum Gnetophyta

GnenophytesGnenophytes GymnospermsGymnosperms Vascular with seedsVascular with seeds 70 species70 species Odd cone bearing plantsOdd cone bearing plants EphedraEphedra is a species that is a species that

produces the drug produces the drug ephedrine used for ephedrine used for weight lossweight loss

Phylum AnthophytaPhylum Anthophyta

Flowering PlantsFlowering Plants Vascular with seedsVascular with seeds Produce flowers for Produce flowers for

reproductionreproduction 240,000 species, largest 240,000 species, largest

phylumphylum Monocots vs. DicotsMonocots vs. Dicots

Parts of the Plant and Parts of the Plant and Their FunctionsTheir Functions

Chapter 4Chapter 4

IntroductionIntroduction Plants are living organisms that Plants are living organisms that

have complex chemical processes have complex chemical processes that direct growth and that direct growth and developmentdevelopment

They have four main body parts They have four main body parts where these processes take place. where these processes take place.

LeavesLeaves StemsStems RootsRoots FlowersFlowers

Plant PartsPlant Parts

Plant PartsPlant Parts

VegetativeVegetative Leaves, stems, rootsLeaves, stems, roots

ReproductiveReproductive FlowersFlowers

LeavesLeaves The food factory of the The food factory of the

plant, producing all food plant, producing all food that is used by the plant and that is used by the plant and stored for later use by the stored for later use by the plant or by animalsplant or by animals

Leaves are the most obvious Leaves are the most obvious and more diverse structures and more diverse structures of plants and leavesof plants and leaves

Vary in shape and size as Vary in shape and size as well as arrangement around well as arrangement around the stem, this helps in plant the stem, this helps in plant classificationclassification

Leaf FunctionsLeaf Functions

Make food for plant (photosynthesis)Make food for plant (photosynthesis) Food/energy storageFood/energy storage Gas Exchange Gas Exchange

Water vaporWater vapor Carbon dioxideCarbon dioxide OxygenOxygen

External Leaf StructureExternal Leaf Structure

Petiole= leaf stalk, stemPetiole= leaf stalk, stem Blade= a larger, usually the Blade= a larger, usually the

flat part of the leaf used to flat part of the leaf used to collect lightcollect light

Midrib= large center vein Midrib= large center vein w/ extensionsw/ extensions

Veins= extensions of midrib Veins= extensions of midrib that give leaves their form that give leaves their form and move water, minerals and move water, minerals and nutrientsand nutrients

Margin= edge of leaf, varies Margin= edge of leaf, varies and aids in plant and aids in plant classificationclassification

Leaf apex: tip of leaf Leaf apex: tip of leaf (round, pointed, (round, pointed, indented, etc.)indented, etc.)

Leaf base: place where Leaf base: place where blade attaches to petioleblade attaches to petiole

Leaf covering: may be Leaf covering: may be waxy or hairywaxy or hairy

Stomata: tiny pores Stomata: tiny pores through which gases through which gases and vapor pass in or out and vapor pass in or out of leafof leaf

Leaf Venation PatternLeaf Venation Pattern

Parallel VenationParallel Venation Veins are parallel to the Veins are parallel to the

midrib and nearly equal midrib and nearly equal in size and extend length in size and extend length of leafof leaf

Grasses, tulips, daffodilsGrasses, tulips, daffodils

Pinnate VenationPinnate Venation Midrib with smaller, Midrib with smaller,

lateral veins branching lateral veins branching from itfrom it

Palmate VenationPalmate Venation Leafs have three or more Leafs have three or more

major veins that extend major veins that extend from the base of the leaf from the base of the leaf blade. Smaller veins blade. Smaller veins branch from these main branch from these main branchesbranches

Monocot vs Dicot Leaf VenationMonocot vs Dicot Leaf Venation

Arrangement of veins in Arrangement of veins in a leafa leaf Monocots, like grasses Monocots, like grasses

have parallel venation, have parallel venation, meaning veins are meaning veins are roughly parallel to each roughly parallel to each otherother

Dicots have pinnate or Dicots have pinnate or palmate net venation, palmate net venation, meaning that the main meaning that the main vein or veins repeatedly vein or veins repeatedly branch to form a branch to form a conspicuous network of conspicuous network of smaller veinssmaller veins

Types of LeavesTypes of Leaves

Simple LeafSimple Leaf Consists of a single leaf Consists of a single leaf

blade and a petioleblade and a petiole

Compound LeafCompound Leaf Made of a petiole and Made of a petiole and

two or more leaf blades two or more leaf blades called leafletscalled leaflets

NOTENOTE

To determine type of leaf, one must first look To determine type of leaf, one must first look for the position of the axillary bud located at for the position of the axillary bud located at the base of the entire leafthe base of the entire leaf

Leaflets of compound leaves do not axillary Leaflets of compound leaves do not axillary budsbuds

Compound leaves may be:Compound leaves may be: Palmately Compound: leaflets come from a point Palmately Compound: leaflets come from a point

at the tip of the petioleat the tip of the petiole Odd Pinnate: leaflets arranged along both sides of Odd Pinnate: leaflets arranged along both sides of

the petiole with a leaflet occurring on the end of the petiole with a leaflet occurring on the end of the petiolethe petiole

Even Pinnate leaflets arranged along both sides of Even Pinnate leaflets arranged along both sides of the petiole without a leaflet occurring on the end of the petiole without a leaflet occurring on the end of the petiolethe petiole

Leaf Arrangement on StemsLeaf Arrangement on Stems

Leaves are attached to stems in patterns that Leaves are attached to stems in patterns that can aid in plant IDcan aid in plant ID Opposite: leaves and buds are directly across from Opposite: leaves and buds are directly across from

one anotherone another Alternate: leaves and buds are alternated or Alternate: leaves and buds are alternated or

staggered along the stemstaggered along the stem Whorled: three or more leaves and buds arise from Whorled: three or more leaves and buds arise from

the same point on the stemthe same point on the stem

Modified LeavesModified Leaves

Bracts: leaves located Bracts: leaves located just below the flowerjust below the flower

Tendrils: extensions that Tendrils: extensions that allow plants to climballow plants to climb

Some thornsSome thorns

Internal Leaf StructureInternal Leaf Structure

Internally, leaves have specialized cells which Internally, leaves have specialized cells which perform very important tasks.perform very important tasks. Epidermis- skin of plant, single layer of cells that protect Epidermis- skin of plant, single layer of cells that protect

plant from loosing moistureplant from loosing moisture Guard Cells- cells that open and close a small space or Guard Cells- cells that open and close a small space or

pore, known as stoma, on the under side of the leaf. They pore, known as stoma, on the under side of the leaf. They allow the plant to transpire, or give off moisture and allow the plant to transpire, or give off moisture and exchange gases such as oxygen and carbon dioxide. Guard exchange gases such as oxygen and carbon dioxide. Guard cells are crescent shaped and as the cell walls become cells are crescent shaped and as the cell walls become turgid, due to water pressure in the cells, they open the turgid, due to water pressure in the cells, they open the stoma.stoma.

Mesophyll- a ground tissue composed of Mesophyll- a ground tissue composed of chloroplast-rich parenchyma cells (loosely chloroplast-rich parenchyma cells (loosely packed, cube-shaped cells with thin flexible packed, cube-shaped cells with thin flexible walls)walls)

Chloroplasts- cells that make foodChloroplasts- cells that make food The green color of the chloroplasts, which gives The green color of the chloroplasts, which gives

green leaves their color, comes from the green leaves their color, comes from the chlorophyll they contain.chlorophyll they contain.

These cells, through a process called These cells, through a process called photosynthesis, manufacture food.photosynthesis, manufacture food.

Palisade mesophyll- a layer of cells that occur Palisade mesophyll- a layer of cells that occur directly beneath the upper epidermis and is the directly beneath the upper epidermis and is the site of the most photosynthesissite of the most photosynthesis

Spongy mesophyll- irregularly shaped cells Spongy mesophyll- irregularly shaped cells surrouinded by large air spaces, which allow surrouinded by large air spaces, which allow oxygen, carbon dioxide, and water to diffuse oxygen, carbon dioxide, and water to diffuse into and out of the leafinto and out of the leaf

Leaf Cross SectionLeaf Cross Section

PhotosynthesisPhotosynthesis

The process by which Carbon dioxide and The process by which Carbon dioxide and water in the presence of light are converted to water in the presence of light are converted to sugar and oxygensugar and oxygen

It is the process that creates the beginning of It is the process that creates the beginning of the food chain for all living things on earththe food chain for all living things on earth

6 CO6 CO2 2 + 6 H + 6 H22O + 672 kcal = CO + 672 kcal = C66HH1212OO66 + 6O + 6O22

Carbon Dioxode + WaterCarbon Dioxode + Water + light energy = Sugar + oxygen + light energy = Sugar + oxygen

Watch and Learn

RespirationRespiration

Plants respire 24 hours a day just like animals Plants respire 24 hours a day just like animals dodo

They consume oxygen and give off carbon They consume oxygen and give off carbon dioxidedioxide

All parts of plants must have adequate access All parts of plants must have adequate access to oxygen in order to surviveto oxygen in order to survive

Plants produce more oxygen than they Plants produce more oxygen than they consumeconsume

Dicot Leaf Cross SectionDicot Leaf Cross Section

Monocot Leaf Cross SectionMonocot Leaf Cross Section

Dicot EpidermisDicot Epidermis

Monocot EpidermisMonocot Epidermis

StemsStems Functions:Functions:

Movement of materials, such Movement of materials, such as the movement of water and as the movement of water and minerals from roots upward to minerals from roots upward to the leaves and movement of the leaves and movement of manufactured food from the manufactured food from the leaves down to the rootsleaves down to the roots

Support of leaves and Support of leaves and reproductive structuresreproductive structures

Sometimes used for storage Sometimes used for storage (Irish Potato)(Irish Potato)

Green stems also manufacture Green stems also manufacture food just as the leaves dofood just as the leaves do

External Stem StructureExternal Stem Structure Leaf Scar: Heart-shaped scar on twig

where last years leaf grew. Node: Growth region on stem. Region

around bud or leaf stem. Internode: segments of stems, between

nodes Bundle Scar: Tiny bumps in leaf scar

where veins enter the leaf from the stem.

Bud: part of plant capable of developing into a Bud: part of plant capable of developing into a new shoot, contains apical meristem tissue and new shoot, contains apical meristem tissue and is enclosed by specialized leaves called bud is enclosed by specialized leaves called bud scalesscales

Lenticels: tiny pores located on the stem that Lenticels: tiny pores located on the stem that allow for gas exchange between the plant and allow for gas exchange between the plant and the environment. Some plants, like cherry the environment. Some plants, like cherry trees, have conspicuous lenticelstrees, have conspicuous lenticels

Terminal Bud: Bud on end of a branch, where all of next years length (of branch) is added.

Lateral (axillary) Bud: Small buds along length of branch that develop into leaves, lateral branches, or flowers.

Apical Dominance: The terminal bud dominates all other lateral buds by giving off hormones. If the terminal bud is cut off, the lateral buds will grow longer.

Internal Stem StructureInternal Stem Structure

Stems are composed of three tissue types Epidermal tissue-Stems are encased by a

transparent epidermis which is usually about one cell thick and which often has trichomes. The trichomes serve various purposes; some plants secrete juices to attract insects, which others have sharp trichomes which often entangle the insects and keep them from feeding while they struggle to free themselves.

Vascular Tissue: tissues that serve as a Vascular Tissue: tissues that serve as a transport system within a plant and act like transport system within a plant and act like strawsstraws Xylem: responsible for the movement of water Xylem: responsible for the movement of water

and nutrients from the roots of a plant to the and nutrients from the roots of a plant to the stems, leaves, and reproductive organsstems, leaves, and reproductive organs

Phloem: responsible for transporting sugars Phloem: responsible for transporting sugars made by photosynthesis from leaves to stem, made by photosynthesis from leaves to stem, roots, and reproductive organs where they will roots, and reproductive organs where they will be used for growth, repair, and reproductionbe used for growth, repair, and reproduction

Ground tissue-Between the epidermis and the ring of vascular tissue in dicots is the cortex. Most cells of the cortex are parenchyma. Cortical cells are photosynthetic in plants and often store starch. In dicots, the ground tissue with the parenchyma cells in the center of the stem is specialized for storage and is called pith. Pith cells are often lignified, arranged loosely, and the pith may contain secretory structures such as laticifers. Because monocots have vascular bundles throughout their ground tissue, their stems do not have a discernible pith; the parenchyma cells in monocot stems are referred to simply as ground tissue

Specialized or Modified StemsSpecialized or Modified Stems

Specialized stems serve as underground food and Specialized stems serve as underground food and water storagewater storage

Bulbs: short flattened stems that bear fleshy food Bulbs: short flattened stems that bear fleshy food storage leaves. At the base of each fleshy leaf there is storage leaves. At the base of each fleshy leaf there is a bud (onion, lily, tulip, narcissus)a bud (onion, lily, tulip, narcissus)

Corms: look like bulbs but are more globe shaped Corms: look like bulbs but are more globe shaped (crocuses and gladioluses)(crocuses and gladioluses)

Rhizome: underground horizontal stem (iris, calla Rhizome: underground horizontal stem (iris, calla lily, ferns) stem tubers are swollen tips of a rhizomeslily, ferns) stem tubers are swollen tips of a rhizomes

Stolon (runner): grows horizontally above ground, Stolon (runner): grows horizontally above ground, produce roots at tip or nodesproduce roots at tip or nodes

Economic Importance of StemsEconomic Importance of Stems

The stems of some The stems of some plants, such as the Irish plants, such as the Irish potato and asparagus, potato and asparagus, are used as food.are used as food.

Others are used as Others are used as building materials, such building materials, such as the lumber from tree as the lumber from tree trunkstrunks

RootsRoots

Roots are underground and therefore, are not Roots are underground and therefore, are not easily visible and are often forgot about. Roots easily visible and are often forgot about. Roots function to:function to: Anchor the plant and hold it uprightAnchor the plant and hold it upright Absorb water and minerals from the soil and Absorb water and minerals from the soil and

conduct them to the stemconduct them to the stem Store large quantities of plant foodStore large quantities of plant food Propagate or reproduce some plantsPropagate or reproduce some plants

Types of RootsTypes of Roots

Taproot: a system of Taproot: a system of roots that has longer and roots that has longer and fewer rootsfewer roots Can reach lower water Can reach lower water

supplies and have large supplies and have large food holding capacityfood holding capacity

Roots may be lost or cut Roots may be lost or cut off when dug upoff when dug up


Fibrous Roots: a system Fibrous Roots: a system with shorter, smaller, with shorter, smaller, and more compact rootsand more compact roots More prone to dryingMore prone to drying Easier to dig up and Easier to dig up and

transplanttransplant


Adventitious Roots: Adventitious Roots: specialized roots that specialized roots that grow from stems and grow from stems and leavesleaves Can prop up plantsCan prop up plants Some absorb water and Some absorb water and

nutrients from the airnutrients from the air Some used in vegetative Some used in vegetative

reproductionreproduction Help plants climb walls Help plants climb walls

(ivy and other vines)(ivy and other vines)

Root StructureRoot Structure

Internal Root StructureInternal Root Structure

Similar to that of Similar to that of the stem. the stem. Made of phloem Made of phloem

and xylemand xylem

External Root StructureExternal Root Structure

Primary Root:Primary Root: First structure to emerge First structure to emerge

from a germinating seed from a germinating seed that immediately absorbs that immediately absorbs water and minerals for water and minerals for growth. growth.

Grows and branches outGrows and branches out Secondary RootsSecondary Roots

Extensions of the Extensions of the primary rootprimary root

External Root StructureExternal Root Structure Root Cap: protection for root tip. Root Cap: protection for root tip.

It produces a slimy substance that It produces a slimy substance that functions as lubricating oil, allowing functions as lubricating oil, allowing the root to move more easily through the root to move more easily through the soil as it grows.the soil as it grows.

Root Hairs: extensions of rootsRoot Hairs: extensions of roots Increase surface area and plants ability Increase surface area and plants ability

to absorb waterto absorb water

Watch MeWatch Me

And Me TooAnd Me Too

FLOWERS-Fruits-SeedsFLOWERS-Fruits-Seeds

http://http://streaming.discoveryeducation.com/streaming.discoveryeducation.com/

search/assetDetail.cfm?search/assetDetail.cfm?guidAssetID=a8b3406b-706c-4148-guidAssetID=a8b3406b-706c-4148-

b416-b416-a7213cc2a5de&tabDisplay=myContea7213cc2a5de&tabDisplay=myConte

ntnt

IntroductionIntroduction To people, flowers are something To people, flowers are something

beautiful that symbolize many beautiful that symbolize many feelings such as love, happiness, feelings such as love, happiness, and sorrowand sorrow

To the plant, they are the means of To the plant, they are the means of reproducing and ensuring their reproducing and ensuring their survivalsurvival

Flowers are considered to be a Flowers are considered to be a highly specialized branches and highly specialized branches and parts of flowers to be leavesparts of flowers to be leaves

Flower PartsFlower Parts

Receptacle: swollen tip Receptacle: swollen tip of the branch where all of the branch where all parts of flower stem parts of flower stem fromfrom

Sepals: outermost whorl Sepals: outermost whorl on flower that surrounds on flower that surrounds and protects the other and protects the other parts of flower before it parts of flower before it opens as it is developingopens as it is developing

Flower PartsFlower Parts Petals: 2nd whorl on flower generally used by Petals: 2nd whorl on flower generally used by

plants to attract insects for pollinationplants to attract insects for pollination

Male Plant PartsMale Plant Parts Stamen: collective name for male partsStamen: collective name for male parts

Anther: contains microsporangia, which produce Anther: contains microsporangia, which produce microspores that develop into pollen grainsmicrospores that develop into pollen grains

Filament: supports the antherFilament: supports the anther

Female Plant PartsFemale Plant Parts

Pistil: collective name for Pistil: collective name for female sex organs which are:female sex organs which are: Ovary: enlarged base of pistil; Ovary: enlarged base of pistil;

contains ovules which develop contains ovules which develop into seeds once fertilizedinto seeds once fertilized

Style: stalk-like part of pistil Style: stalk-like part of pistil leading from ovary to:leading from ovary to:

Stigma:sticky or hairy part of Stigma:sticky or hairy part of pistil that is capable of catching pistil that is capable of catching pollen grainspollen grains

Types of FlowersTypes of Flowers

Complete:Complete: Contains both male and Contains both male and

female parts within the female parts within the same flowersame flower

IncompleteIncomplete Contains male or female Contains male or female

parts, but not bothparts, but not both

Flower InflorescencesFlower Inflorescences To help identify the plants, flower To help identify the plants, flower

forms are grouped as to their forms are grouped as to their position or arrangement on a position or arrangement on a stem.stem. Solitary Flowers: one flower Solitary Flowers: one flower

on a stemon a stem Inflorescence: arrangement of Inflorescence: arrangement of

flowers on a stemflowers on a stem

Inflorescence TypesInflorescence Types

Cyme: Cyme: Takes on several formsTakes on several forms Usually flat toppedUsually flat topped Baby’s breathBaby’s breath

SpikeSpike Elongated inflorescence with Elongated inflorescence with

a central axis along which are a central axis along which are sessile flowerssessile flowers

Sessile flowers are attached Sessile flowers are attached directly without a stem or directly without a stem or stalkstalk

gladiolusgladiolus

RacemeRaceme Elongated inflorescence with Elongated inflorescence with

a central axis along which are a central axis along which are simple pedicels of more or simple pedicels of more or less equal lengthless equal length

Snap dragons, delphiniums, Snap dragons, delphiniums, Scotch broom, and stalkScotch broom, and stalk

PaniclePanicle Elongated inflorescence Elongated inflorescence

with a central axis along with a central axis along which there are branches which there are branches that are themselves that are themselves branchedbranched

Astilbe, begoniasAstilbe, begonias

CorymbCorymb Flat topped inflorescence Flat topped inflorescence

having a main vertical having a main vertical axis and branches of axis and branches of equal lengthequal length

yarrowyarrow

UmbelUmbel Inflorescence having Inflorescence having

several branches arising several branches arising from a common pointfrom a common point

Queen Anne’s lace, Queen Anne’s lace, amaryllisamaryllis

SpadixSpadix Spike with a thickened, Spike with a thickened,

fleshy axis, usually fleshy axis, usually enveloped by a showy enveloped by a showy bract called a spathebract called a spathe

Calla lily, anthuriumCalla lily, anthurium

CatkinCatkin Spike, raceme, or cyme Spike, raceme, or cyme

composed of unisexual composed of unisexual flowers without petals flowers without petals and falling as a unitand falling as a unit

Willows, alders, birchWillows, alders, birch

PollinationPollination

Pollination occurs when pollen grains are transferred from the Pollination occurs when pollen grains are transferred from the anther to the stigmaanther to the stigma

Pollen grains then germinate and a pollen tube grows down the Pollen grains then germinate and a pollen tube grows down the style until it reaches the ovules in the ovarystyle until it reaches the ovules in the ovary

Fertilization occurs when one sperm nucleus fuses with the Fertilization occurs when one sperm nucleus fuses with the egg cell nucleus, forming a zygote that will become a seedegg cell nucleus, forming a zygote that will become a seed The other sperm nucleus fuses with two nuclei in the ovule to create the The other sperm nucleus fuses with two nuclei in the ovule to create the

endospermendosperm

Cross PollinationCross Pollination

Controlled cross-pollination is an important technique Controlled cross-pollination is an important technique used by plant breeders in developing new cultivarsused by plant breeders in developing new cultivars Occurs when pollen grains from the flowers on one plant Occurs when pollen grains from the flowers on one plant

transfer to the stigmas of flowers of another planttransfer to the stigmas of flowers of another plant Occurs between closely related plantsOccurs between closely related plants Hybrids: offspring resulting from cross-pollinating two Hybrids: offspring resulting from cross-pollinating two

different varieties of a speciesdifferent varieties of a species Done to improve traits or characteristicsDone to improve traits or characteristics

SeedsSeeds

Mature, fertilized Mature, fertilized ovules, or eggs, that are ovules, or eggs, that are contained in a fruitcontained in a fruit Range in size from a few Range in size from a few

millimeters to several millimeters to several centimeterscentimeters

Can be flat, cylinder Can be flat, cylinder shaped, or roundedshaped, or rounded

Distributed my animals, Distributed my animals, wind, fire, etc.wind, fire, etc.

All viable (livingAll viable (living