Field Botany – Spring 2013. Course Website
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Transcript of Field Botany – Spring 2013. Course Website
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
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
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
Rank Ending Example
Kingdom Plantae
Division (Phyla) - phyta Magnoliophyta
Class - opsida Magnoliopsida
Order - ales Magnolioales
Family - aceae Magnolioaceae
Genus Magnolia
Species grandifolia
Rank Ending Example
Kingdom Plantae
Division (Phyla) - phyta Magnoliophyta
Class - opsida Liliopsida
Order - ales Poales
Family - aceae Cyperaceae
Genus Carex
Species radiata