Author Archives: ctsai@uoregon.edu

Terms

Terms to Know

forest

Leaves:

Leaf Arrangement: 

  • alternate vs. opposite
  • simple vs. compound
  • 2-ranked vs. spiral
  • decussate
  • single vs. bundled needles
  • flat sprays

Leaf Margins: 

  • entire
  • serrate
  • doubly serrate
  • revolute

Leaf Venation: 

  • arcuate
  • 3-veined from base of leaf
  • palmate
  • pinnate
  • penniveined

Leaf Shape: 

  • needle like
  • scale-like
  • awl-like
  • palmately lobed
  • pinnately lobed

Leaf Appearance: 

  • persistent, thick & leathery
  • pubescent
  • thin & somewhat translucent
  • stomatal bloom

Petiole Features: 

  • petiole
  • sessile
  • distinct glands on petiole
  • leaf base parrallel to twig

Twigs:

Buds: 

  • bud scales
  • cap-like
  • imbricate
  • valvate
  • terminal clusters
  • naked
  • sessile
  • stalked
  • spur shoot

Leaf Scars: 

  • peg-like projections
  • round smooth scars

General Features: 

  • armed
  • exfoliating bark
  • ribbed, ridged green stems
  • scurfy

Pith Features: 

  • solid
  • triangular
  • chambered

Cones and Fruits:

Cones: 

  • imbricate
  • peltate
  • cone bract

Samaras: 

  • single
  • double

Back to Main Page 
Coniferous Species 
Broadleaf Species

Tree ID

Trees and Shrubs
Identification Terms:
Visual Definitions on the Web

Welcome to our homepage. This page has been designed to aid people in their understanding of the basic terminology used in dichotomous keys and in tree anatomy. As residents of the Pacific Northwest, the terms and the plants we have concentrated on are those that are prominent in this area. This page was constructed as a term project for Forest Biology (BI 307) at the University of Oregon. The 22 identified species on this page correspond to the species that students of BI 307 class are required to know by sight. This page was also designed to assist students of Environmental Education (PEOL 453).

Hopefully this will act as a guide and a supplement to provide visual images and explainations that written definitions cannot. Good luck!

Terms to Know

Broadleaf Species

Coniferous Species

This page was constructed by Tony Leiserowitz, Shana Pennington and Indigo Teiwes under the advisory of Alan Dickman. If you have any questions or comments please contact Alan Dickman at adickman@oregon.uoregon.edu.