Variation in texture of leaves. 1. lettuce 2. Tobacco. leaves - 1 - humidity acts 2. Hairy leaves - guy - Dr Sample Muller Tobacco 1. Shaved 2. left hairs on } Evaporation about the same. Hairs seem to slow up change. Roots - 1. In desert the roots are shallow. 2. Each type of plant has a distinctive root habit. - Roots penetrate & feed at different levels. Some plants are much more flexible ecologically than others. The less flexible the more specialized the environment must be. leaves arranged in a mosaic pattern. 1. Remot & each leaf trying to get greater illumination; Effect of light, moisture, habitat on leaf variation.