PBIO 250 Lecture Notes

James L. Reveal

Norton-Brown Herbarium, University of Maryland

Methods of Identifying Vascular Plants

identification of vascular plants specimen determination
information necessary for identification:
    (1) knowledge of taxonomic methods, characters and terms
    (2) knowledge of manuals, herbaria and other resources
    (3) experience in the identification of plants
identification is based on a scheme of classification
plant names permit retrieval of information
accurate identification are critical
scientific names permit communication of ideas keys
make critical examinations of all characters

hand lens
needles
contrasting characters
families to genera to species
diagnostic characters
key characters
dichotomous
couplet(s)
secondary key characters
indented key
bracket key
keys should be:
    (1) dichotomous
    (2) nouns then adjectives
    (3) all features stated in contradictory terms
    (4) consistent or major features first, secondary key characters next
    (5) avoid vague terms or generalities
manuals
floras
monographs and revisions
checklists - see the Checklist of the Vascular Plants of Maryland
single-access key
polyclave keys
computer-based keys
computer-stored keys

Selected examples of current resources - see the plant databases portion of FindIt

• Internet Directory for Botany: Checklists, Floras, Taxonomic Databases
  
• Atlas of Florida Vascular Plants
• Atlas of the Vascular Plants of Utah
• CalFlora Database
  
• Checklist of the Vascular Plants of Texas
• Flora of China
• Flora Mesoamericana
• Flora North America
• North American online floras and checklists
  
• PLANTS
  
• The provisional Global Plant Checklist
• South Carolina Plant Atlas
• A Synonymized Checklist of the Vascular Flora of the United States, Canada, and Greenland

Last revised: 21 Jan 1999