greek112 It looks like the one on the right is one of the many coleus varieties and there are many (some truly gorgeous), and the one on the left seems to be an arboricola (dwarf scheflera). Hope this helps.
A presumption would be: 1) To keep water from leaking from the pot onto the furniture, or, 2) It is really a plastic bag to do the same, AND, to keep the moisture content high in the pot. (Preclude a high rate of evaporation). Or, I could be wrong on both counts. Sorry.
I might guess that as it's in a classroom, perhaps the foil is to increase humidity in order to root a cutting.
Kudos to mamamac lol...a co-worker took a piece of the plant and unsuccessfully tried to root it in water. That is why it was in a plastic cup with aluminum foil over it to keep the water from evaporating. Unfortunately, it never rooted, so if anyone has any advice on how to go about rooting plants in water or otherwise, I really would appreciate it. It's a very nice plant :)
I have tried to root Hawaiian schefflera with rooting gel, and only one of four attempts worked out. I've had better luck with air layering.
There are many 'gardening' books that can give you the details, but basically, you would proceed about as follows: On an upright stem, girdle the stem with a sharp knife, cutting only the bark just below a node on the stem. Remove a very narrow band of the cut bark. Apply a rooting agent such as Rootone or other similar rooting hormone, wrap the cut portion with damp moss (i.e. sphagnum) and then loosely wrap the moss with clear plastic wrap and use twist ties or string on the top and bottom of your wrap to prevent the moisture from evaporating. After three to six weeks, if you have been successful, you should see roots inside the plastic. At that time you can cut the rooted portion from the stem, and trim the stem to just above the next lower lobe. You should then have a cloned new plant to pot plus the potential new shoots to grow from the node on the stubbed branch from which your new plant was propagated. It isn't brain surgery, but it can be fun. Some plants start more easily than others. Hit the web for 'Plant Propagation Methods' or similar words, and have fun!
