Samples of plants were obtained during the campus tour. In order survive in the harsh climate of deserts, plants must adapt in function, reproduction, support, and defense. Although plants on campus are watered frequently, they live in a mostly xeric environment. Three types of cacti were observed: organ pipe, prickly pear, and saguaro. The organ pipe contains no leaves and has narrow stems that carry out photosynthesis and store water. Neither the saguaro nor prickly pear cacti have leaves, but both have a highly modified form of a leaf called the spine. Spines are highly modified leaves because they do not carry out photosynthesis. Spines protect the plant from predation and prevent water loss as stomata in leaves are highly susceptible to water loss. Fruit trees like the sour orange must grow deep roots to store an obtain water. Flowers observed had small leaves and are not bright green in color. The leaves have a waxier cuticle to help seal in water. The observation that the investigation will be focused on the size of leaves or modified leaves. Hypothesis
Desert plants will have smaller leaves because it must minimize water loss through stomata and evaporation in order to survive in arid environments such as the Sonoran desert where water is a scarcity. Methods
The independent variable will be the type of plant observed and the dependent variable will be the size of the leaf in terms of length and diameter to produce a surface area. First, pick plants with highly modified leaves: the pine and cacti. Then, pick plants that are not native to the region: the bellflower, candy stripes moss phlox, and the sour orange. Three leaves from each plant will be picked to take into account variation to leaf size. Then, the length and diameter at the center (or where the diameter is the greatest) will be measured. Average the lengths and diameters for each type of plant. A t-test will be used to compare the differences...