This lesson explores basic internal and external physiology of trees.

Trees are characterized as woody perennial plants, generally having an upright form and a well-defined trunk; some experts suggest that plants must be capable of growing to a mature height of 20' to be classified as trees. Hundreds of different species have been identified and classified in the Southeastern United States, but most have a few characteristics in common.

Inside a tree

Show the video "Tree Detective" (18 minutes) available from your local Forestry Commission office. You may wish to preview the tape in order to reinforce the important teaching points. 

Ask a student to bring in a 10-12" diameter cross-section of a pine trunk. Try to obtain a similar cross-section of sable palmetto. (Sometimes landscape companies can provide these if they are replacing dead palmettos.) Ask the students to compare the two cross-sections, looking for similarities and differences. Is the South Carolina State Tree really a tree? (No. It is a member of the grass family whose trunk is very similar to a corn stalk!) Note: caution the students as they handle the palmetto. The fibers in the trunk are very sharp.

Parts of a tree

The High School shop class may be able to prepare the "tree cookies" for you. Dead branches of red cedar work well, but almost any dead branch about 2" in diameter will do.

Reference Resources / Education

Contents / Lesson 1 / Lesson 2 / Lesson 3 / Lesson 4 / Lesson 5 / Lesson 6 / Lesson 7