Materials | Field guides of area trees, images of plants, computers with Internet access (optional), copies of handouts
Warm-up | Have students respond to the following prompt: What is a tree? Provide a definition, an example, a non-example and a drawing.
For a more extended warm-up, have students sort and categorize images of a variety of plants, including trees, into groups. You might gather images from gardening magazines, seed catalogs or visit an online plant database or photo gallery. Then have students discuss and explain their rationale for each category, and develop a working definition of “tree.” (Although this may not seem difficult, use the exercise to encourage students to practice their classification skills and use of precise language to express their ideas.)
Next, ask students to compare their definition with this quote from today’s Times article: “What, then, is a tree? Precise definitions vary, but most of them mention the words “tall” and “woody,” and add that a tree has a single self-supporting stem (i.e., a trunk) that branches well above the ground.”
Ask: How similar or different is your definition? Did you choose words like “tall,” “woody,” “stem” or “trunk”? Does your definition accurately describe and include all trees?
Related | In her Opinionator blog post “Tree-mendous,” evolutionary biologist Olivia Judson reflects on the lives, significance and evolution of trees, nominating this informal grouping as April’s “Life-form of the month”:
Some trees — sequoias and eucalypts, for instance — can be prodigiously tall, reaching heights of 90 meters (295 feet) or more. And some are prodigiously old. Plenty of species can live for four, five or six centuries, and some can keep going for several thousand years. The oldest living tree — which is also one of the oldest living beings — is thought to be a bristlecone pine, Pinus longaeva. It is certainly more than 4,600 years old, and by some reckonings, it celebrates its 4,842nd birthday this year. But however you count, when it was a sapling, the great pyramids of Giza had not yet been built.
