Taxonomy,Taxonomy,Classification,Classification,

and Identificationand Identification

Karl HagenbuchKarl Hagenbuch

Department of Biological SciencesDepartment of Biological SciencesSan Antonio CollegeSan Antonio College

TaxonomyTaxonomy

= the study of naming, describing and = the study of naming, describing and classifying organisms, including the classifying organisms, including the

rules, theories, principles and proceduresrules, theories, principles and procedures

Taxon = Taxon = a group of organisms recognized a group of organisms recognized at any level of a taxonomical hierarchyat any level of a taxonomical hierarchy

(e. g. Family, Class) (e. g. Family, Class)

ClassificationClassification= the orderly arrangement of organisms into a hierarchal = the orderly arrangement of organisms into a hierarchal

system that is derived from an accumulation of system that is derived from an accumulation of information about the individual organisms, the end result information about the individual organisms, the end result

expressing an interrelationshipexpressing an interrelationship

Why?Why?

Because it provides humans with a means to address Because it provides humans with a means to address organisms and their relationships to one anotherorganisms and their relationships to one another

Because it allows humans to make inferences about Because it allows humans to make inferences about unfamiliar organismsunfamiliar organisms

Because it is in our natureBecause it is in our nature

ClassificationClassificationSystems:Systems:

Artificial = based on obvious or convenient items of Artificial = based on obvious or convenient items of information called characters (e.g. flower color, locality).information called characters (e.g. flower color, locality).

Natural = based on morphological features that Natural = based on morphological features that give the sense of correlation with those of give the sense of correlation with those of another organism. (e.g. trees, grasses)another organism. (e.g. trees, grasses)

Phylogenetic = based on the proposed lineage Phylogenetic = based on the proposed lineage derived from a wide variety of information.derived from a wide variety of information.

AristotleAristotle

Greek PhilosopherGreek Philosopher

First to propose a system First to propose a system of classificationof classification

Scala NaturalaeScala Naturalae

Two types of animals:Two types of animals:•With bloodWith blood•Without bloodWithout blood

TheophrastusTheophrastus

Greek PhilosopherGreek Philosopher

Father of plant taxonomyFather of plant taxonomy

Classification of plants Classification of plants was based on:was based on:•Mode of generationMode of generation•LocalityLocality•SizeSize•UsefulnessUsefulness

Carl von LinnéCarl von Linné

Swedish botanist, zoologist, and Swedish botanist, zoologist, and physicianphysician

First to illustrate the usefulness First to illustrate the usefulness of binomial nomenclatureof binomial nomenclature

Developed the modern Developed the modern taxonomic hierarchytaxonomic hierarchy

Modern Hierarchy Modern Hierarchy (Biological Classification)(Biological Classification)

• Domain – Eukarya• Kingdom – Animalia• Phylum – Cordata• Class – Mammalia• Order – Primates• Family – Hominidae• Genus – Homo• Species – Homo sapiens

• Current system recognizes 3 Domains:• Eukarya:• Kingdom Animalia• Kingdom Plantae• Kingdom Fungi

• Archaea & Bacteria

• The previously recognized Kingdoms of• Protista & Monera have been disolved

Modern Taxonomic HierarchyModern Taxonomic Hierarchy

Carolus LinnaeusCarolus Linnaeus

= a two-word name consisting of a generic name and a specific = a two-word name consisting of a generic name and a specific epithetepithet

Binomial NomenclatureBinomial Nomenclature

Specific epithets:Specific epithets:Descriptives – Descriptives – Quercus macrocarpa Quercus macrocarpa

= Oak with big fruit= Oak with big fruitHonorifics – Honorifics – Quercus buckleyi Quercus buckleyi

= Oak named for Mr. Buckley= Oak named for Mr. BuckleyLocalities – Localities – Quercus virginiana Quercus virginiana

= Oak first described in Virginia= Oak first described in Virginia

Phylogenetic ClassificationPhylogenetic Classification= the evolutionary history of a species or group of species

Typically represented as a phylogenetic tree (cladogram) a branching a branching diagram showing the diagram showing the evolutionary evolutionary relationships among relationships among various biological various biological species or other taxa species or other taxa that are believed to have that are believed to have a common ancestora common ancestor

http://static.newworldencyclopedia.org/7/70/Phylogenetic_tree.svg

The Pylogenetic TreeThe Pylogenetic Tree

TimeTime

Species 1Species 1 Species 2Species 2 Species 3Species 3

Plant ClassificationPlant Classification

Current classification systems follow the recognized Current classification systems follow the recognized taxonomic hierarchy, however, there is always some taxonomic hierarchy, however, there is always some disagreement as to the membership requirements of disagreement as to the membership requirements of various taxavarious taxa

The CoreThe Core

Gymnosperms and Angiosperms

Angiosperms• plants with vascular (circulatory) tissues• they produce flowers • reproductive unit is a seed produced within an

enclosed ovary

GymnospermsGymnosperms• plants with vascular (circulatory) tissuesplants with vascular (circulatory) tissues• they lack flowers they lack flowers • reproductive unit is a seed produced on scales reproductive unit is a seed produced on scales

in a cone-like structurein a cone-like structure

Non-vascular land plantsNon-vascular land plants•reduced plants that lack vascular reduced plants that lack vascular (circulatory) tissues(circulatory) tissues•they neither have flowers nor produce they neither have flowers nor produce seedsseeds•reproductive unit is a sporereproductive unit is a spore

Ferns and fern alliesFerns and fern allies•plants with vascular (circulatory) tissuesplants with vascular (circulatory) tissues•they neither have flowers nor produce they neither have flowers nor produce seedsseeds•reproductive unit is a sporereproductive unit is a spore

IdentificationIdentification

= the assigning of an existing name to an = the assigning of an existing name to an unknown organismunknown organism

MethodsMethods

Expert assistance – local university, Expert assistance – local university, school, museumschool, museum

Comparison method – guide books, Comparison method – guide books, internetinternet

Dichotomous key – local manuals, florasDichotomous key – local manuals, floras

Dichotomous KeyDichotomous Key

Keys based on a sequence of pairs of Keys based on a sequence of pairs of contrasting statementscontrasting statements

The user chooses the statement that better The user chooses the statement that better describes the plant in questiondescribes the plant in question

Each time a choice is made a number of plants Each time a choice is made a number of plants are eliminatedare eliminated

Eventually the number of possible Eventually the number of possible identifications is reduced to oneidentifications is reduced to one

Dichotomous KeyDichotomous Key

1. Growth habit an herb1. Growth habit an herb1. Growth habit a vine, shrub or tree1. Growth habit a vine, shrub or tree

. . . . . . . . . . . . 2. . . . . . . . . . . . 2 . . . . 4. . . . 4

4. Growth habit a vine4. Growth habit a vine4. Growth habit a shrub or tree4. Growth habit a shrub or tree

. . . . . . . . . . . . 5. . . . . . . . . . . . 5 . . . . . . . 7. . . . . . . 7

7. Growth habit a shrub7. Growth habit a shrub7. Growth habit a tree7. Growth habit a tree

. . . . . . . . . . . . 8. . . . . . . . . . . . 8. . . . . . . . . . . . 30. . . . . . . . . . . . 30

Dichotomous KeyDichotomous Key

30. Leaf arrangement opposite30. Leaf arrangement opposite30. Leaf arrangement whorled or alternate30. Leaf arrangement whorled or alternate

. . . . . . . . FraxinusFraxinus . 31. 31

31. Leaves simple31. Leaves simple31. Leaves compound31. Leaves compound

. . . . . . . . . . . . . . . 32. . . . . . . . . . . . . . . 32 . . . . . . . . . . . . 44. . . . . . . . . . . . 44

32. Venation palmate32. Venation palmate32. Venation pinnate or reticulate32. Venation pinnate or reticulate

. . . . . . . . . . . . . . WashingtoniaWashingtonia. . . . . . 33. . . . . . 33

Leaf TypesLeaf Types

Leaf TypesLeaf Types

Leaf TypesLeaf Types

Leaf TypesLeaf Types

Leaf TypesLeaf Types

Dichotomous KeyDichotomous Key

33. Margin entire33. Margin entire33. Margin toothed33. Margin toothed

. . . . . . . . . . . . . . . 34. . . . . . . . . . . . . . . 34 . . . . . . . . . . . . . . 39. . . . . . . . . . . . . . 39

34. Lobes present34. Lobes present34. Lobes absent34. Lobes absent

. . . . . . . . . . . . . . . 35. . . . . . . . . . . . . . . 35 . . . . . . . . . . . . . . 37. . . . . . . . . . . . . . 37

35. Blades palmately lobed35. Blades palmately lobed35. Blades pinnately lobed35. Blades pinnately lobed

. . . . . . . . . . PlatanusPlatanus. . . . . . . . . 36. . . . . . . . . 36

Dichotomous KeyDichotomous Key

36. Lobes rounded36. Lobes rounded36. Lobes pointed36. Lobes pointed

. . . . . . Quercus macrocarpaQuercus macrocarpa . . . . . . . . . . Quercus buckleyiQuercus buckleyi

Thank YouThank You

It is both an honor and pleasure to It is both an honor and pleasure to speak before the Master Naturalistspeak before the Master Naturalist

I wish you all continued successI wish you all continued success