What Can Leaf Size and Shape Tell Us?

Questions & Prompts:

• Which leaves do you think grow in hot, dry conditions? Which leaves do you think grow in wet, shady conditions? Why?

• Identify patterns between the leaves. What can these patterns tell you?

• Choose one of the leaves above. Draw the leaf with as much detail as possible. Can people guess which leaf you chose based on your drawing?

• Choose one of the leaves above. Write a descriptive paragraph. Can people guess which leaf you chose based on your writing?

• What similarities do you see? What differences?

• Describe the plant that you think made each of these leaves. How big is the plant? Where does it live? Does anything eat this plant?

• Do any of these leaves look like the leaves in your community?

Adaptations

Small leaves have less total surface area than large leaves, and they lose less water than large leaves. Overheating can also be a problem for large leaved plants in dry, hot environments. Wide leaves heat up more than narrow leaves of the same length. In general, small, narrow leaves are well adapted to hot, dry, sunny environments.

Leaves from wetland environments have the opposite challenge! The rainforest has four layers (emergent, canopy, understory, and forest floor). Each of these layers blocks out sunlight. The forest floor gets almost no light at all! Leaves in these environments have adapted to low light and lots of water. Large leaves arranged horizontally absorb the most light possible. Because these plants have plenty of access to water, they can keep large leaves alive!