Botany Week 8

This week we expanded our study of leaves to learn about transpiration, which is pretty cool.  Plants transpire, which is not terribly different from how we perspire, except what they transpire is just water.  Interestingly, even though plants need a great deal of water, they use very little in photosynthesis and most of it (90-99%, the sources I used did not fully agree) is put right back out through the stomata of the leaves as water vapor.

This can be more easily understood with a very simple science experiment:  Put a clear plastic bag over a few leaves and seal the opening.  Wait an hour and there will be a mist of water in the bag.  Wait a few hours and the mist will thicken into droplets.  Wait a day and there will be a measurable amount of water in the bag.

I arrived at PEP early to set up a bag on a tree and that worked just as planned.  I had also planned to set up a bag at the start of my class, but that did not work out because the very moment our class started, it rained.  Still rain here is nearly always a brief event and once it stopped, I took the class out to see my first bag and to collect a leaf.

During our rain delay, we talked about how leaves change color...and how they don't do that here.  Actually, some trees do change color in Florida, but it is much later, much less dramatic, and mostly in North Florida.  Most of the types of trees that change color do not grow well here and local trees are commonly palms.  I think the notable exceptions in our particular neighborhood are the Royal Poinciana, which grows like a weed here, but is from Hawaii, and the Live Oak, which is considered a semi-evergreen, that is, it's leaves may stay green until they fall off.  And probably here they do.  We do see a lot of fallen leaves as the dry seasons ends, but they are all brown.  We also have lots of sea-grape, gumbo limbo, banyan, slash pine, and mangrove.

After the kids collected  a leaf, we used the UF/IFAS Illustrated Leaf Glossary to classify the parts of the leaf and then glued the leaf to a page and labeled it's parts.  It was pretty simple compared to some of the lessons we've done before!

I took the suggestion from the Apologia book to have the kids consider different scenarios for what happens to an individual leaf and had them draw a comic strip on a long thin piece of paper.  They seemed to really like it - several kids wanted to read theirs or take it out to show a parent.  It did not accomplish anything particular to Botany, but as a language arts person, I liked how it crossed the spectrum of education to let the kids think creatively.  Here is a super crummy cell phone picture of the extra large comic I made as an example:

And I sent each kid away with a zip top gallon bag to do the transpiration experiment at home over a longer period of time.

My main "take away" this week was that the kids can only add a little new information to subject they already feel familiar with and any new information needs to be somehow attached to something they already understand well.  I did already know that, but tend to forget it!  So in short, this week was one of the more successful classes because we only learned one thing - plants transpire.