Tree Identification by the Use of Leaves
Elaine E. Messal Henry Clay Elementary
13231 South Burley
Chicago IL 60633
312-535-5600
Objectives:
1) Utilize the phenomenological approach to motivate students at the sixth grade
level to understand how leaf arrangement and structure can be used for tree
identification.
2) Develop the ability and desire to use concepts presented to identify all the
trees included in the mini-teach plus the remaining ones in the neighborhood.
Materials needed:
1) Five motivating clue statements on posters
2) Two large sheets of construction paper for every two students
3) Four sheets of typing paper for each student
4) Six leaf samples from the local area for every two students
5) Prepared leaf drawings for performance assessment
6) Herbarium collection and leaf keys for display
Strategy:
1) The night or morning before the lesson, collect six different leaves from the
local area for each pair of students. Press them between two folded sheets of
construction paper and seal them with masking tape.
2) Divide the class into groups of two and give each pair a sealed set of leaves
plus eight sheets of typing paper.
3) Display the five motivating clue statements which follow and have the
students guess what is in each set.
clue 1 One of us is believed to be the oldest and largest of all living
things.
clue 2 Some extinct species of us have been petrified.
clue 3 Some of us have received names of famous people such as Abraham
Lincoln and General Sherman.
clue 4 Always use our multicultural scientific names, which are the same
throughout the world, if you don't want to make a mistake naming us.
clue 5 The part of us that manufactures food is squeezed between the papers
on your desk. Name that part.
Note: Clues 1, 2, and 3 refer to the coniferous giant sequoia tree,
and the final answer for all five clues is LEAVES OF TREES.
4) Each pair of students who are sure of the answer should raise their hands and
secretly give the answer to the teacher. Jelly candy leaves may be given as a
reward.
5) When everyone knows that the enclosed objects are leaves the sets are opened
and each leaf is sketched by each student.
step 1 A sheet of typing paper is placed over each leaf one at a time.
step 2 Students use their pencils and sketch over each leaf with an acute
angle between the pencil and the paper so the side of the graphite is
used. They must press hard to show entire leaf blades, margins, and
petioles.
6) After the leaves are sketched, ask the students to observe and identify the
following:
Deciduous Trees
Margins (entire, serrate, lobed, toothed)
Venation (parallel, palmate, net)
Shapes (oval, linear, heart, fan, different shapes from the same tree)
Types (simple, compound, double compound)
Arrangement (alternate, opposite, whorled)
Evergreen Trees
Needlelike (Bundles of 2-5, clustered)
Scalelike
7) Show a leaf identification key to develop the concept of identification by
the use of the above structures. Name the six leaves sketched.
8) Show other examples of leaves in the local area by using an herbarium
collection or fresh samples.
9) Take the class on a walk around the school building or local area and
identify trees by using the leaf structures and arrangements observed and
discussed in class.
10) Introduce the importance of using scientific names. They are the same
throughout the world. The same common names have been given to more than one
plant and improper identification has occurred. Asimina triloba is deciduous
and Carica papaya is evergreen, and both have been called paw-paw or pawpaw.
The common name sycamore has also been given to completely different trees.
11) Assign students to write reports about trees which are native to an area
or country representing their cultural heritage.
Performance Assessment:
1) Ask students to identify the trees studied on their walk when the same
trees are observed again on the return trip.
2) Leaves sketched in class and observed during the walk should be labeled
correctly in a station to station test conducted in the classroom. Place
numbers on each sketch, fresh sample, or herbarium sheet, and tell the
students to write the correct name for each leaf as they are held up or
observed at a specific location.
3) Require students to define or draw two examples of different margins,
venation, shapes, types, and arrangements.
References:
Petrides, George A., A Field Guide to Trees and Shrubs.
Zim, Herbert S., and Martin, Alexander, Trees A Guide to Familiar American
Trees.
Elias, Thomas S., The Complete Trees of North America Field Guide and Natural
History.
http://www.tree-identification.com/
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