Class the Second

So yes, this is a little late.  I’ve been sick.  And busy.  But today is the day; I am less busy, and no longer sick!

The second class was fascinating.  Best of all, we had flowers at our tables!

Of course, the reason we had flowers were to check their stems, to see if they are monocot or dicot.  Monocot circulatory systems are complex, dispersed throughout the stem; dicot plants have the system arranged in a circle. This is easily distinguished when you observe the stem.  We had lilies and a couple of dyed vegetables, celery and asparagus, to illustrate this.  Celery is a dicot system, asparagus is monocot.  The lilies were monocot.  It was fascinating.

We categorized different plants by their use; this was much more difficult than it sounds.  many trees and plants have many different uses; some are vegetables, some are landscaping, some are ground-cover or houseplants, and some fit several categories.  Ivy, for instance, can be both a house plant and a ground cover.

I also learned more about trees and how their circulatory system works.  For some reason, I had thought bark was there for protection only.  Apparently, this is not true; part of the tree’s circulatory system is IN the bark!  This seems obvious when I think about it, but I generally do not spend much time wondering about the function of tree bark.

We talked about different types of growth issues in trees, and I learned more about how trees grow, how their root system works, and what kinds of things affect their growth. I learned a new term, girdling, which refers to the removal of bark around a tree.  Because the zylem, the structure that brings nutrients from the leaves and branches to the roots, is found in the bark, the tree will be able to leaf the next year, but will die because the tree is unable to transport the nutrients produced in the leaves back to the roots for storage.

I also learned about stem circles.  These are small circles on the stem, that are created by the leaf bud each winter.  These can be used to gauge how old a tree is; you can count each stem circle.  These can also give you an idea of whether the tree was under stress through an unfavorable growing season, etc.  On unfavorable years, the length between stem circles will be quite short.  However, one of the other students at my table pointed out that at a certain point, trees do not grow long stems each year, depending on the age of the tree.

We did not get all the way through the appointed lesson, so we left part of it for Week 3. Coming up, botany!!


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