Some folks were tired of being cooped up inside. They joined me on my walk in the woods identifying different trees at Matthaei Botanical Gardeens. It was a cold day on Saturday but over 20 people signed up for my class. We spent almost 2 hours walking the trails and identified over 20 trees, shrubs and vines.
One tree that we saw often on our walk was the Tulip Tree, also called Yellow Poplar. It’s an important lumber tree particularly down south. It grows a very straight trunk and if it’s surrouned by other trees, the lower branches die and fall off early , so it has few knot-holes , thus making smooth knot-hole free boards.
We also saw lots of White Ash. Unfortunately, most of them were dead from the Emerald Ash Borer. Washtenaw County, where the Gardens is, was one of the first counties to be quarantined because of the E.A.B.. So all of our big Ash trees are dead. At the Gardens many were cut down near the trails for safety reasons. On the downed trees we could easily see the tunnels left by the borer larvae. They chewed their way through the cambium layer right under the bark. The cambium is the essential vascular system that keeps the tree alive.
We also looked on the bark for the telltale “D” shaped holes where the borer entered the tree. I hadn’t realized we had so many Ash Trees at the Gardens until they stood out as dead trees.
The death of this magnificient tree is going to make a lot of botanists and tree lovers feel very negative about globilization. (The E.A.B. was brought into our country inside wood packing cases from a foreign country.)
The group was awed by the big Poison Ivy vines that we saw. Some were almost 3 inches thick and thirty feet high, growing up some tall trees. P.I. has rootlets all along the vine that attach to the trunk of the tree. It is not a parasite because it doesn’t steal any nutrients from the tree. The short rootlets just anchor the vine to the trees so it can grow upward to the sunlight. We saw branches of the vine sticking out, which differentiates the P.I. from the Virginia Creeper vine, which also has rootlets for clinging to the bark of a tree. Poison Ivy has 3 leaflets. Virginia Creeper has 5 leafllets and is not poisonous. Did you know that a person can get the rash from P.I. even in the winter time and even from the roots in the ground. The oils that irritate us are present even when the plant is dormant.
Once I get started in the woods, I tend to want to keep on going to see what is around the next bend. But we were cold after a hour and a half, so we started on back to the building.
There are a number of good Tree identification guides that you can use. The one we like best at the Gardens is “Michigan Trees” by Barnes and Wagner. Both were professors at University of Michigan. Dr. Wagner, sadly, died a few years ago. But Barnes is still giving classes with the Community Education Program at the Matthaei Botanical Gardens.
Bye for now, Judy