Sunday, August 08, 2010

Drawing Inferences about a Tree

When I visited Scott Brewer's home recently, I discovered a magnificent tree in his yard.

I asked if it was a Sycamore tree. Scott and his mother said it was a beech tree. I said the massive tree must be at least 200 years old. Scott said it was 100 years old.

I had recently purchased a lovely book, John Laird Farrar, Trees of the Northern United States and Canada (Blackwell, 1995). I was determined to confirm that the tree was a beech tree. I turned to pp. 268-269 and I saw:

I then snatched a leaf from the tree and the leaf looks like this:

The leaf looks very much like the leaf of the American beech tree shown in the book.
But then I noticed:

1. The book entry states that there are 9-14 lateral veins on each side. The leaf snatched from the tree appeared to me to have 8 lateral veins on each side. Scott said he saw 9 lateral veins.

2. The book entry said that American beeches are as much as 25 meters high. The beech in Scott's yard, it seemed to me, was taller.

3. An entry in the book states that "[b]ark remains smooth even on mature trees." The bark at the bottom of the tree was gnarled and contorted. But Scott's mother later noted that the tree had become infested with a fungus.

5. An entry in the book states the veins of the American beech trees end in a tooth. I wondered if those were or were not "teeth" I saw on the leaf.

Then I looked over at an entry on the lower part of page 269. That entry deals with the European Beech. I had ignored that entry because the European Beech is a non-native species and I thought it unlikely that the tree in the back yard had been planted there 200 years ago. But then I looked at the picture of a leaf of the European Beech and it looked less serrated than the pictured leaf for the America Beech. Moreover, the entry for the European Beech said that its leaves have 5-9 veins on each side.

So is the tree in the back yard an American Beech or a European Beech?


The dynamic evidence page
It's here: the law of evidence on Spindle Law. See also this post and this post.