Today in science the students worked to identify a tree, using the parts I brought to school from my camping trip in early August.
Here’s what we had to help us:
- seed pods
- a small seedling
That was a lot of information to help the students figure out the species, but not quite enough.
One student tried using this dichotomous key from Wisconsin, but he got stuck when he needed to identify the pith in the stem. David couldn’t get beyond this step because we didn’t have a stem. There was missing information, so the next time I saw the tree, I plucked off a stem and brought it to school.
- the seeds, pods, and seedling we had earlier
- the leaf arrangement on the compound leaf
- the leaf arrangement on the stem
- inside the stem (the pith)
Students got busy searching on Sweet Search for terms like “dichotomous key”, “deciduous tree” (once they figured out how to spell it — their teacher had been no help), and “native Iowa trees” (the only clue I had given them).
Mason found a great dichotomous key, from Iowa State University, which I was sure would help him figure it out, but as he went through the questions, he got stuck on. Then I joined him, and I got stuck too. We knew it was broadleaf and compound leaf, and we thought the leaves were arranged oppositely. That’s where we became stuck because after that all the trees mentioned had samaras, which are small winged seeds. Our tree definitely had no samaras.
What would you say? These are the examples we had. It seemed we had a bit of both.
This photo of alternate leaf placement is so different than the leaves we have. Maybe that’s another reason we thought that was the wrong way. In the meantime, other students had gone ahead down the alternate path, which ended up being a wise move. The students went on to choose between thorns and no thorns (ours has none), smooth or toothed leaf margins (smooth), singly or doubly compound (doubly compound).
Finally, with a click on the last doubly compounded link the tree came up, and it was definitely our tree, the one we have in our classroom — The Kentucky Coffee Tree. (Gymnocladus dioicus)
Here are more pictures of the mysterious tree that has now been identified!
You can find these Mystery Tree images and more on Flickr. You can use them for a mystery tree activity, for none of them have been tagged with the real name of the tree.