Field Botany – Spring 2013

Course Website

• http://courses.knox.edu/bio316/

Botany Labs

Textbook

How many plant species are there?

• Illinois – over 3200 vascular plants

• Northeastern North America – over 4600 vascular plants (Gleason and Cronquist)

• California – over 4400 vascular plants

From Gleason and Cronquist 1991

How many plant species are there?

• Illinois – 58,000 square miles – over 3200 vascular plants

• Costa Rica – 19,600 square miles – over 8,000 vascular plants

How many plant species are there?- total in 2010

• 16,000 Bryophytes (mosses, liverworts and hornworts)

• 12,000 Pterophytes (ferns and fern allies)

• 1021 Gymnosperms

• 282,000 flowering plants (Angiosperms)

• 311,000 total plant species

• Some add in green algae – 8500 species

How many endangered plant species?

• In 1997 the IUCN (International Conservation Union) Red Data list for plants rated 34,000 species as endangered out of 60,000 species evaluated

• Then changed evaluation procedures – IUCN now rates 8,000 species as endangered out of 11,000 species evaluated

• UK (very well known flora) lists 20% of species as endangered

• Likely that 1 out of 4 plant species is endangered

Aceraceae – The Maples

Maple samaras (fruits)

Asteraceae – The Sunflowers, Asters

AnnualSunflower

Goldenrod

Poaceae – The Grasses

Ammophila – Beach grass

Field Trip to Missouri Botanical Garden – April 18

Plant Collection

Taxonomy

Definitions

• Taxonomy - the study and description of the variation of organisms, the investigation of the causes and consequences of this variation, and the manipulation of the data obtained to produce a system of classification

• Classification (as process) - the production of a logical system of categories, each containing any number of organisms, which allows easier reference to its components, the kinds of organisms

• Classification (as object) - is that logical system itself

Definitions cont’d

• Identification - naming of an organism by reference to an already existing classification system

• Taxon - any taxonomic grouping - division, class, family, genus, etc.

• Description - statement of the characteristics of a taxon

• Characters that contribute to a taxonomic description are known as taxonomic or systematic characters

Definitions cont’d

• Diagnosis - shortened description covering only those characters (diagnostic characters) which are necessary to distinguish a taxon from other related taxa

• flora (lower case) - plant life of a given area

• Flora (upper case) is a book or other work describing the flora of a given area

Classification

• Need for classification is absolute – it is only by naming organisms and grouping them in recognizable categories that we can begin to understand the vast array of diversity that exists

Southern magnolia – Magnolia grandifolia

Rank Ending Example

Kingdom Plantae

Division (Phyla) - phyta Magnoliophyta

Class - opsida Magnoliopsida

Order - ales Magnolioales

Family - aceae Magnolioaceae

Genus Magnolia

Species grandifolia

Star sedge – Carex radiata

Rank Ending Example

Kingdom Plantae

Division (Phyla) - phyta Magnoliophyta

Class - opsida Liliopsida

Order - ales Poales

Family - aceae Cyperaceae

Genus Carex

Species radiata

Hierarchies of plant taxonomy – from Stace