Identifying Trees and Developing
a Class Herbarium

Introduction
What do you see first when you look at a group of trees? They are not all alike. The easiest way to identify a tree is to use a tree key. There are many different structures you need to know in order to use the key correctly. The definitions are usually at the beginning of the tree identification key, accompanied by a picture to describe how to use them.

Once you think you have identified your tree, the pictures in the book will help you to see if you are correct. An even better method is to start a herbarium collection at your school so that you can compare your sample to locally grown specimens. This exercise is in four parts; collecting, identifying, pressing, and mounting the specimens.

Questions

  1. What is the name of this tree?
  2. Can I match it with our resource books?
Hypothesis
Students should make up their own before continuing.

Objectives

  1. Identify the trees found on your school grounds.
  2. Identify the major parts of a tree needed for identification.
  3. Demonstrate the proper technique for collecting and mounting a herbarium specimen.
  4. Create a quality herbarium specimen for the class collection.
Materials

Pruning shears Notebook for class data
Plant press 8.5" x 14" copy paper
Tree identification key Newspaper
Tree and shrub books White glue (Elmer's)
Hebarium stickers 2' x 2' plexiglass
Wax paper
Procedure

Identification:

  1. Find the tree assigned to you and use the tree identification key to identify the specimen.
Collecting:
  1. Find a branch on the tree, with the leaves in good condition, that can be reached by one member of your group. Be sure to gather a twig and leaves that will fit on the piece of paper, and not larger.
  2. Check with your teacher, then use the pruning shears to make the cut at a diagonal so that the pith can be seen.
  3. Place the samples on the inside of a half folded newspaper.
  4. Data collected by the group is recorded on the attached sheet, or in your logbook. These records may be important if the identification of your specimen is questioned.
  5. The date, location on the grounds, city, and person who identified it should be noted.
Pressing:
  1. On returning to school with your specimens in the newspapers, the teacher will give each specimen a number before the sample is put in the press.
  2. Specimens should not hang outside the newspaper when placed in the press, and should be piled neatly.
  3. First put down one of the wood frames of the press, followed by 2 cardboard aerators. Next, place one blotting page before the newspaper containing the leaf, followed by another blotting page and the other leaves. Insert one or two cardboard aerators before the next layer.
  4. Once all the collected materials are stacked, put two cardboard aerators and the wood frame on top.
  5. Place the straps around each end and then pull as tight as possible.
  6. The press can be left to dry slowly over 48-96 hours. Some type of device to heat air and blow it through the plant press can be used for faster drying, which preserves color better. Ovens are too hot. Leaves can tolerate a maximum temperature of 130oF.
Mounting:
  1. Once the plants are dried, they can be left in the paper, or can be mounted on 11 x 17 inch herbarium paper. Check to see if the pressed plants will fit on the paper before gluing. If necessary, prune to make the leaves fit correctly on the paper.
  2. Secure the plant parts to the paper with a solution of 60% white glue and 40% water solution.
  3. Place glue on a plexiglas or other large smooth surface and gently lay the specimen in the glue solution until all parts are covered.
  4. Lift specimen carefully on to the paper and center it so that all parts are visible.
  5. Apply the herbaruim labels, or place the needed information in the lower right hand corner.
Results:
  1. Prepare a data sheet for the class inventory of all collected specimens. Include tree common name, genus and species name, code number, and the location where it was found on you school site.
Discussion Questions
  1. We identified trees by leaves, what are three other plant parts that could be used to identify trees? Why?
  2. What are three advantages of knowing how to identify a tree?
  3. Describe the two most useful characteristics of tree identification that you used. Why?
  4. Do you think that some closely related trees would be hard to identify? Explain.
Conclusions Write a statement explaining how much of your hypothesis was correct. Is there anything that occurred during this exercise that you didn't expect to happen? If you were to do this exercise again, how would you do it differently?

Terminology
(This is for all levels. Ask your teacher which words you need to know.)

Needle-like leaves Broadleaf with net venation
scale-like pinnate / palmate
bundles alternate / opposite
tufts compound / simple
single needles stem
deciduous length / hairy
drooping branches main vein
sheath rough texture
brittle margins smooth / toothed
stiff regular / irregular
4-sided serrated / lobed
3-sided entire / wavy
hairy twigs venation
scales palmate / pinnate
fan-shaped parallel
shapes heart / ovate

Leaf Morphology Stem and Bud Morphology
blade terminal bud
midrib lateral bud
stipule bud scale
stem terminal bud scale scar
leaf leaf scar
petiole lenticel
bud bundle trace
leaflet pith

 

Herbarium____________________

Scientific name_________________

____________________________

Habitat_______________________

Locality______________________

Collector_____________________

Determined by_________________

No._________________________ 

 

Herbarium____________________

Scientific name_________________

____________________________

Habitat_______________________

Locality______________________

Collector_____________________

Determined by_________________

No._________________________ 

 

Herbarium____________________

Scientific name_________________

____________________________

Habitat_______________________

Locality______________________

Collector_____________________

Determined by_________________

No._________________________ 

 

Herbarium____________________

Scientific name_________________

____________________________

Habitat_______________________

Locality______________________

Collector_____________________

Determined by_________________

No._________________________ 


To Download Herbarium Worksheet PDF To Download Herbarium Worksheet PDF

Table A:

Group Name _______________________
Date_________________________

Condition Key:
H = healthy
B = bark damage
I = insect damage

Tree Codes and Inventory

Tree
Number
Common
Name
Scientific
Name
Tree
Type

Condition

Notes

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To Download Table A PDF To Download Table A PDF


Table B:

Group Name _______________________
Date_________________________

Key and Notes:




Tree Number and Structures

Tree
Number
Bark
Color
Twig
Color
Leaf
Shape
Flower
Color
Fruit
Type
Avg. Twig
Growth
19__
Avg. Twig
Growth
19__
Avg. Twig
Growth
19__

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To Download Table B PDF To Download Table B PDF

Table C:
Student Tree Identification Chart

Group Name _______________________
Date_________________________

Specimen No._____________________
Common Name______________________ Scientific Name______________________


CHECK OFF THE IDENTIFIED CHARACTERISTIC:

EVERGREEN:

____ evergreen
____ Needle
____# of needles in bundle
. ____ deciduous
____ scale
. ____ awl
____ length of needles

Description of cone _______________________________________________________________________________
Color of needles___________________________________________________________________________________

BROADLEAF:
____ evergreen . ____ deciduous

Leaf:
____ opposite
____ simple
____ palmate
. ____ alternate
____ compound
____ pinnate

Margin:
____ entire
____ lobed
. ____ serated
____ # of lobes
. ____ wavy
____ other margins

Venation:
____ palmate . ____ pinnate . ____ parallel

Possible extra data:
____ tree height
____ length of petiole
____ flower color
____ fruit type
. ____ tree spread
____ bud length
____ season
_____ fruit color
. ____ bark color
____ fruit size
To Download Student Tree Identification Chart - Table C PDF To Download Student Tree Identification Chart - Table C CPDF

Plant Parts Checklist:
Student Guide

____ Parallel
____ Rosette
. ____ Palmate
____Alternate
. ____ Pinnate
____Opposite
____ Entire
____ Awl shaped
. ____ Serrated
____ Lobed
. ____ Double serrated
____ Pinnately compound
____ Palmately compound
. ____ Simple
____ Blade
____ Petiole
____ Ovate
____ Lanceolate
. ____ Rachis
____ Obovate
____ Spatulate
. ____ Leaflet
____Deltoid
____Cordate
____ Needle
____ Stamen
____ Bundle scar
____ Node
____ Internode
. ____ Petal
____ Pistal
____Bud scale
____ Leaf scar
____ Lenticel
. ____ Sepal
____ Terminal bud
____ Lateral bud
____ Bud scale Scar
____ Dehiscent
____ Multiple fuit
. ____ Indehiscent
____ Pod
. ____ Berry
____ Pome
____ Rhizome
. ____ Drupe
____ Root hair
. ____ Pith
____Bulb

Numbered pressed materials illustrating some of these terms are included with the Forester's Trunk inventory. Preparing these samples could also be a class project to build on over several years.

To Download Plants Parts Checklist Student Guide PDF To Download Plants Parts Checklist Student Guide PDF

Background Information
Once the students have accomplished the task of learning to use the tree identification key (May Watts Tree Finder from Forester's Trunk), they should be ready to develop the class herbarium. Following the student format, each student group should be assigned a specific number of specimens to collect.

Target Group
Elementary through high school, with modifications necessary in the amount of collecting each level completes.

Timeline:
This lab can be done with all the students at the beginning of the unit. The students need to understand and be able to use the tree identification key (May Watts Tree Finder from the Forester's Trunk). These keys are not all inclusive but the students can usually identify the species of the trees. Other resources are available in the trunk to check on their identification. Herbarium specimens from previous classes can also be used to confirm identification. This is one of the reasons to have one or more herbarium specimens for each of the trees identified on your site.

Placement of Lab in the Curriculum
This lab is appropriate at the time you are covering other data exercises or classification lessons from your text. It can also be used to get students to gather, organize and prepare data for future analysis. This lab is best if scheduled at the beginning of the year, especially since the trees are in full leaf at that time.

Student Learning Objectives
1. Compare living trees by applying a classification scheme to them.
2. Identify errors made in identification by other students.
3. Gather specimens for a herbarium.

Evaluation
Collection and preparation of herbarium mounts can be used as the major tool in assessment. The correct identification of the tree and/or tree parts can be used for pre- or post-evaluation.

Preparation and Teaching Tips
The teacher will need to provide newspaper for pressing the plants, white glue that has been mixed with water in a 60/40 solution for mounting leaves, and a smooth surface to spread the glue on. The best size paper for making the herbarium mounts is 8.5 x 14 inches. The teacher may have to instruct students on the proper method for collecting leaves without denuding trees. Assigning trees to student groups once they have been numbered can alleviate many collection problems and group concerns. The students need to be familiar with many of the terms in the lab exercise and the identification key. This can be accomplished by using the pressed samples and the slide set that is part of the Forester's Trunk inventory.

When filling in the Student Identification Chart (Table C), have the students list the pages in the tree identification key (May Watts Tree Finder from the Forester's Trunk) that they followed to identify the tree. This can be used to check their work. These can be kept with the pressed plant parts in folders for the students to check.

Discussion Questions and Conclusion Answers
The questions are all of a higher order nature, and can be done by the group or individually. Answers will vary.

Blowouts
1. Students can go into the community or to local forest preserve and develop herbarium sets for each area separately. Students can build a plant press and collect all the needed materials for continuing this exercise.
2. Use plant parts checklist to develop class set of materials, similar to the one found in the Forester's Trunk.

References
1. May Watts Tree Finder, May Watts Theilgaard. Nature Study Guild, Berkeley, CA. 1991.
2. Selecting and Planting Trees, The Morton Arboretum, Lisle, IL. 1990.
3. Manual of Woody Plants, Michael A. Dirr. Stipes Publishing Co., Chamapign, IL. 1975.
.

Plant Parts Checklist:
Elementary Level
Teacher Guide

_1__Parallel
____Rosette
_2__Palmate
_4__Alternate
_3__Pinnate
_5__Opposite

____Entire
____Awl shaped
____Serrated
_7__Lobed
____Double serrated
_6__Toothed

_8__Pinnately compound
_9__Palmately compound
_10__Simple
_11__Blade

_12_Petiole
____Ovate
____Lanceolate
____Rachis
____Obovate
____Spatulate
_13_Leaflet
____Deltoid
____Cordate

____Needle
____Stamen
____Bundle scar
____Node
____Internode
____Petal
____Pistal
____Bud scale
____Leaf scar
____Lenticel
____Sepal
____Terminal bud
____Lateral bud
____Bud scale scar

____Dehiscent
____Multiple fruit
____Indehiscent
___Pod
____Berry
.

____Pome
____Rhizome
____Drupe
____Root hair
____Pith
____Bulb

These are the numbered pressed materials in the kit, the remaining could be a class project to build on over the next several years.

To Download Plant Parts Checklist: Elementary Level PDF To Download Plant Parts Checklist: Elementary Level PDF
Plant Parts Checklist:
Middle School Level
Teacher Guide
_1__Parallel
_4__Rosette
_2__Palmate
_5__Alternate
_3__Pinnate
_6__Opposite

____Entire
_9__Awl shaped
_10_Serrated
_7__Lobed
_____Double serrated
.

_8__Pinnately compound
_12_Palmately compound
_11_Simple
_13_Blade

_14_Petiole
_17_Ovate
____Lanceolate
_15_Rachis
____Obovate
____Spatulate
_16_Leaflet
_20_Deltoid
____Cordate

_18_Needle
_25_Stamen
_21_Bundle scar
____Node
____Internode
_24_Petal
_27_Pistal
____Bud scale
____Leaf scar
_23_Lenticel
_26_Sepal
_19_Terminal bud
_22_Lateral bud
____Bud scale scar

____Dehiscent
____Multiple fruit
____Indehiscent
____Pod
____Berry
.

____Pome
_29_Rhizome
____Drupe
_30_Root hair
_28_Pith
____Bulb
To Download Plant Parts Checklist: Middle School Level PDF To Download Plant Parts Checklist: Middle School Level PDF

Plant Parts Checklist:
High School Level
Teacher Guide

_1__Parallel
_7__Rosette
_2__Palmate
_4__Alternate
_3__Pinnate
_5__Opposite

_6__Entire
_9__Awl shaped
_10_Serrated
_11_Lobed
_8__Double serrated
.

_12_Pinnately compound
_13_Palmately compound
_14_Simple
_15_Blade

_16_Petiole
_19_Ovate
_20_Lanceolate
_17_Rachis
_22_Obovate
_21_Spatulate
_18_Leaflet
_25_Deltoid
_24_Cordate

_23_Needle
_37_Stamen
_29_Bundle scar
_30_Node
_31_Internode
_35_Petal
_38_Pistal
____Bud scale
_33_Leaf scar
_34_Lenticel
_36_Sepal
_26_Terminal bud
_27_Lateral bud
_32_Bud scale scar

_39_Dehiscent
_44_Multiple fruit
_40_Indehiscent
_45_Pod
_41_Berry
.

_43_Pome
_49_Rhizom
_42_Drupe
_47_Root hair
_46_Pith
____Bulb
To Download Plant Parts Checklist: High School Level PDF To Download Plant Parts Checklist: High School Level PDF

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