Lesson at a Glance

Groups of students use inferring skills to determine how the leaves of some common plants are adapted to various environmental conditions and how silverswords are adapted to various island zones.

Key Concepts

From a single colonizing plant species, many new related Hawaiian silversword species evolved, becoming quite different from their ancestors. Rainfall, sunlight, temperature, and elevation affect the size and form of plants.

Objectives

Students will be able to describe how plants adapt to various environmental conditions.

Time

2-3 class periods

Subject Areas

Science, Hawaiian studies

Materials

Student data sheet (provided)
15 leaves

Preparations

Make one copy of the Hawaiian vegetation zones sheet. Gather five sets of leaves from three plants with the following leaf characteristics: hairy/fuzzy (geranium), thick (jade plant), large and dark (ti).

Teaching Suggestions

1. Divide the class into five groups. Distribute the three different leaves to each group and ask students to describe how the leaves are different.
   
   
2. Ask students if they think the thick leaves would be better adapted to a dry, sunny environment or a wet, shady environment. Discuss their reasons. Then ask them to determine to which kind of environment (dry/sunny or wet/shady) the remaining two leaves are best adapted.
   
   
3. Distribute the student data sheet and lead a discussion about leaf characteristics and plant forms in relation to climatic conditions.
   
   
4. Distribute and review the Hawaiian vegetation zones sheet. Add a bog to the sheet in the upper elevation of the rainforest. Explain that bogs are located in areas where there is heavy rainfall and poor drainage.
   
   
5. Discuss how plants (and animals) are able to adapt to different habitats. Be sure that students are aware that according to Darwin's theory of evolution, random mutations result in a few beneficial adaptations which are passed on to offspring.

Extended Activities

Create a new form of silversword! Have students design new silversword relatives adapted to different conditions (such as the city, or the beach).

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