Returning to school this August, I discovered a redesigned landscape around the Parish Hall and school. I was happy to see a section planted with asiatic jasmine (Trachelospermum asiaticum), a Florida-friendly plant that is drought-tolerant and needs little care. It is one of my favorite ground covers.
I used the jasmine to show the process of transpiration for my science students. We placed a Ziploc bag around a branch of jasmine and sealed it as much as possible. We also placed a Ziploc bag around a branch with no leaves as a comparison. The jasmine was in full sun with temperatures in the 80′s F. We left for 20 minutes to walk out to the student garden to check on the progress of the garden.
When we returned, the bag with the jasmine leaves had a layer of moisture inside the bag. The other bag had no moisture. Students realized the moisture was the result of transpiration. Transpiration helps to pull water up from the roots through the stem and into the leaves of the plant. (see water movement in celery stalk) Water is needed for photosynthesis in the leaf, but some water vapor leaves the leaf through small openings and increases the amount of water vapor in the air. Transpiration is an important part of the water cycle.