Plant Taxonomy (Systematics)

Naming

Classifying

Identifying

Plant Systematics

Naming– give an organism a precise scientific name

– Homo sapiens L.

– ICZN, ICBN, ICMN

Plant Systematics

Classifying– organize into groups

– Primata• Hominidae

– Homo sapiens

Plant Systematics

Identifying– finding the name

of an organism that has already been named and classified

Dichotomous Keys

A series of paired choices that leads to the correct name of an organism

Collecting, Preparing and Preserving Plants

Collecting, Preparing and Preserving Plants

Polynomial Nomenclature

Ranunculus calycibus, retroflexus, pedulculis falcatis, caule erecto, folis comopositis

Polynomial Nomenclature

Ranunculus calycibus, retroflexus, pedulculis falcatis, caule erecto, folis comopositis

“The buttercup with bent-back sepals, curved flower stalks, erect stems and compound leaves”

descriptive, precise

Binomial Nomenclature

- Began 1753, Species Plantarum– Carolus Linnaeus 18thC Sweden

Ranunculus calycibus Genus species

Binomial Nomenclature - Began 1753, Species Plantarum

– Carolus linnaeus 18thC Sweden Genus species same species name

– Cercis canadensis L.– Solidago canadensis L. Authority

Rules: International Code of Botanical Nomenclature (ICBN)– ICZN, ICMN

ICBN Rules Genus treated a noun; species as adjective suffixes usually agree in gender Male female neuter us a um is is re er ris o

Lactuca hirsut_ Lathyrus hirsut_ Vaccinium hirsut_

Binomials Often describe some feature

Incorporate the name of a person or place

perpetuate a classical name

Binomials– Quercus alba “white oak”– Quercus macrocarpa “burr oak”

– All tree genera are treated as female!

– Veronica noveboracensis (L.) Michx.• CHANGE OF CLASSIFICATION

Linnaeus’ Kingdoms

Plants Aristotle

Animals Aristotle

Kingdoms

Plants Aristotle Gr 4thC BC

Animals Aristotle Gr

Protista E. Haeckel Ger 19thC

Fungi R H Whitaker USA 20thC

Archebacteria (Archaea) C. Woese USA 20th C

Eubacteria (Bacteria) C. Woese USA 20th C

Domains

Species

A distinct types of organism capable of breeding with other members of its own kind - but not with other species….

Basic category in biological nomenclature

Varieties (subspecies)

Sargent

Quercus alba L. var. alba Quercus alba L. var. latiloba Sarg.

If Q. latiloba was a new species?– Quercus latiloba Sarg.

hybridization

Q. velutina X Q. rubra X Q. palustris

Echinacea pallida

Echinacea paradoxa

Echinacea pallida X paradoxa

Relationship between Genus and Species

Genus - a group of related species

Quercus (oaks) Carya (hickories)– rubra - ovata– velutina - cordiformes– alba

Related 1. Have similar characteristics (may

hybridize) 2. Have a common ancestor back in

evolutionary time velutina rubra alba

Related 1. Have similar characteristics (may

hybridize) 2. Have a common ancestor back in

evolutionary time ovata cordiformes

Evolution (implied by classification)

Organisms that are placed in the same genus are believed to be more closely related than organisms from other genera.

Phylogenetic Hierarchy Kingdom

– Division (Phylum)• Class

– Order» Family» Genus» species

Natural System

Our present system attempts to group organisms in accordance with natural (evolutionary) relationships.

– Homology

Natural System

Our present system attempts to group organisms in accordance with natural (evolutionary) relationships.

– Homology• internal structures, embryology, DNA, proteins

– Analogy• based on superficial characteristics• outward form and function

Standard Endings (ICBN)

Division: phyta Class: opsida Order: ales family: aceae Genus: species:

Taxa

Division: Anthophyta Coniferophyta Pterophyta “flowering “pines,spruces, “ferns”

plants” firs” » Magnoliopsida

» Liliopsida

Classes of Flowering Plants

Magnoliopsida– dicots - 2 embryonic

leaves– taproot– branching leaf veins– flower parts:2s, 4s,

5s

Liliopsida– monocots - 1

embryonic leaf– adventitious roots,

branching– parallel leaf veins– flower parts: 3s

Classification of Burr Oak: Kingdom: Plantae: Plantae Division: Anthophytaphyta Class: Magnoliopsidaopsida Order: Fagalesales family: Fagaceaeaceae Genus: Quercus species: macrocarpa

binomial: Quercus macrocarpa