Similar to a previous lesson on animal structure, I begin this lesson with a brief round of singing “Head, Shoulders, Knees, and Toes”. When discussing structure (of any kind!), I like to break it down into pieces to help the students better understand that part:whole connection. When we are finished, I ask, “Who thinks that a leaf is just a leaf?”. My students know me better than to assume that kind of simplicity, so they smartly answered “Never!” "There are some very interesting parts of a leaf. We are going to study more about how the parts create a whole." This line of discussion accesses prior knowledge and sets a nice foundation to the rest of the lesson.
When I was looking at resources for this collection of plant based unit, I came upon a great site. Hidden Villa is a farm near my school that hosts field trips. They have a great K-5 curriculum that highlights the natural world. While it didn’t specifically go into leaf structure, it did give me ideas to set a positive tone and encourage students to go further with their exploration. I knew I want them to dive deeper into the structure of a leaf so they can better understand the Science of it.
I hold up a picture of a leaf diagram that I enlarged to ledger size for easier viewing. I tell them “We get to be “Botanists” again today. In order to be Botanists though, we need a specimen to study so we’re going to make it easy and use this picture. Botanists observe and record things to help themselves and other people learn. Can someone share something they observe in this picture?” “I see a line in the leaf.” “Come up and point to that line and help me tell the class about it.” They come up and point to the blade, the ridge down the center of the leaf. “This is a ridge. Say ‘ridge’.” “Ridge!” To facilitate the correct terms and pronunciation, I almost always have students repeat unfamiliar terms so make them more comfortable using them. “A ridge is like the backbone of the leaf, the part that anchors the rest of the structure. The smaller lines coming from it are called ‘veins’. Say ‘veins’.” “Veins” “Veins hold up the leaf and are filled with vessels that take food, water, and minerals to the plant.”
“There are two other important parts of the leaf that I want to share with you. The first is the ‘lobe’.” I gesture with my hands for them to repeat ‘lobe’. “The lobe is the part that determines the shape of the leaf. The last part I want you to know is called the ‘petiole’. This part comes off of the leaf. Lots of people will call it the stem but that’s the wrong term. The stem is actually the part that connects to the petiole.” It’s important to me to use academic Science vocabulary when I teach lessons like this, even if the subject is simple. I’d rather students move forward with correct vocabulary than use the wrong terms. To support this instruction, I pass around two more pictures of leaves that are close up views of these leaf structures. “Take a quick look at these pictures. Talk with a partner and see if you can identify some of the parts we talked about.” When they are finished viewing the pictures, I collect them and move on.
At this point, I tell them that we get to be like famous botanists and record what we see. “We are going to draw a leaf of any shape and label the parts that we’ve just learned. Practice them with me.” I hold up the Leaf Diagram paper as I talk. We name them together as I count them off on my fingers with one hand and point to them on the picture with my other hand. “Rib..veins..lobe..petiole”. As we finish up, I give a signal to sit back while I ask the Daily Helpers to pass out a diagram paper to each student. To make it easier, I include the names of the leaf parts on the paper, as well as list them on a chart that's accessible to the students. You never know where and how they'll access information so I like to provide them with as many places as possible.
• First, decide the leaf shape you’ll draw. Consider looking around the room for an idea.
• Next, draw the leaf shape on the paper.
• Then, label the parts of the leaf. You can either write the label to draw a line to the part.
The leaf diagram essentially acts as a pass/fail formative assessment because they show mastery over the material by correctly sketching and labeling the leaf. This diagram also acts as a model in the sense that the students are able to recreate a leaf using their perspective. Any time you can add an element of student ownership, it enhances the absorption and application of the material, making it much easier to explain to others. The activity takes about ten minutes by design. I give them a one-minute warning with a hand-clap pattern before I ask them to neatly stack their papers on the table and return to their carpet squares.
Once we are all seated, I ask for a Daily Helper as a volunteer. I use them as an example as I point to their body and ask for the leaf equivalent. “What is this on a leaf?”, I ask while pointing to the spine. “Ribs!” I continue on, pointing to the ribs (veins), arms (lobes), and legs (petiole). While our body parts are not totally botanically connected to the leaf's , this Wrap Up gives them a fun way to practice important vocabulary.