I’ve always loved leaves. When I was young, I viewed the leaf covered forest floor as if it were covered with treasure. I couldn’t wait to dig in and see what I could discover. I regularly told my parents that I was making a leaf collection for school, just so I could get permission to explore the woods. To make it a truthful story, I always turned my collections over to my elementary school teachers. The confused teachers would usually explain that I could better use my time by working on the assigned lessons, instead of trying for extra credit with a never ending series of leaf collections. A little show of confusion and fear usually earned me the extra credit despite the teacher’s initial reaction.
What you find on the woodland floor is not always a true representation of the species mix on that site. At first glance the Blue Jay Barrens woods would appear to be primarily oaks. This is just an illusion created by the fact that the oaks are usually the last to drop their leaves, so they cover everything that has fallen before.
In some ways, collecting leaves was somewhat pointless. Many species of trees cannot be identified solely from the leaf. Oaks are a good example. Depth of sinuses, number of lobes, shape and length of points are all variable. A single tree can exhibit leaves of such varied shapes that you might mistake each shape for a different species. To make a positive ID, the leaves must still be attached to the tree so you can also view the buds and twigs.
Even if you can’t be sure of the oak identification, you can make some accurate generalizations. Round lobe tips indicate species in the white oak group and pointed lobe tips designate red oak group. A large number of similar leaves usually indicate that the source is close by. Leaves can be carried long distances by the wind, so a few scattered leaves of one type could mean that they have been blown in from some other area.
I spend a lot of time sifting through the leaves. You may not be sure of your identification from just a single leaf, but you may suspect the presence of a particular tree based on the evidence. I’ve found several interesting species by first finding their leaves in the fall and then searching for the tree the next summer. The leaves can suggest possibilities and identifying a possibility is typically the first step towards discovering the reality.
I’ve always loved leaves. When I was young, I viewed the leaf covered forest floor as if it were covered with treasure. I couldn’t wait to dig in and see what I could discover. I regularly told my parents that I was making a leaf collection for school, just so I could get permission to explore the woods. To make it a truthful story, I always turned my collections over to my elementary school teachers. The confused teachers would usually explain that I could better use my time by working on the assigned lessons, instead of trying for extra credit with a never ending series of leaf collections. A little show of confusion and fear usually earned me the extra credit despite the teacher’s initial reaction.
What you find on the woodland floor is not always a true representation of the species mix on that site. At first glance the Blue Jay Barrens woods would appear to be primarily oaks. This is just an illusion created by the fact that the oaks are usually the last to drop their leaves, so they cover everything that has fallen before.
In some ways, collecting leaves was somewhat pointless. Many species of trees cannot be identified solely from the leaf. Oaks are a good example. Depth of sinuses, number of lobes, shape and length of points are all variable. A single tree can exhibit leaves of such varied shapes that you might mistake each shape for a different species. To make a positive ID, the leaves must still be attached to the tree so you can also view the buds and twigs. 
Even if you can’t be sure of the oak identification, you can make some accurate generalizations. Round lobe tips indicate species in the white oak group and pointed lobe tips designate red oak group. A large number of similar leaves usually indicate that the source is close by. Leaves can be carried long distances by the wind, so a few scattered leaves of one type could mean that they have been blown in from some other area.
I spend a lot of time sifting through the leaves. You may not be sure of your identification from just a single leaf, but you may suspect the presence of a particular tree based on the evidence. I’ve found several interesting species by first finding their leaves in the fall and then searching for the tree the next summer. The leaves can suggest possibilities and identifying a possibility is typically the first step towards discovering the reality.
Well, this was informative. Thank you, Steve, as always.
ReplyDeleteYou're Welcome Katie.
ReplyDeleteThis reminds me about an incident on a hike the other day. We were on a stretch through upland oak-hickory forest when we spotted some enormous sycamore leaves. Normally a bottomland tree, I knew it is also an early pioneer species and we began looking for the tree. No characteristic white-barked branches could be seen anywhere in the canopy, so we looked on the ground, found the area where the leaves were concentrated, the hiked west a little bit (into the direction of prevailing winds here), and found a few small saplings at the edge of a disturbed area. The leaves must have been a good 10-12" diameter! It was fun solving the "mystery".
ReplyDeleteHi Ted. Around here we often find medium sized Sycamores growing over wet weather springs on the hillsides. Eventually the tree outgrows its water supply and dies back. When the tree dies, the spring begins to flow again. The spring flow diminishes as the tree grows, until all outward signs of the spring disappear.
ReplyDelete