Chapter III  

The Forest Floor

Part III - Intro to Botany!

Learning the Language of Plants!

An Introduction to Botany.

(Parents we encourage you to join your child in this lesson!) 

Fancy clothes!

Plants look all kinds of different ways to fit their lifestyle and environment. We are going to do a little overview of some of the different ways plants “dress” so that you can learn to notice their differences and similarities. The more you practice looking closely at all of the finer details, the more the world of plants will open to you!

Your Botany Chapter...

In your journal, you will create your own chapter on botany to help learn plant patterns. 

Draw each of the pictures below in your journal so you can take them with you on your adventures!

 

Part I - Leaf Shape

 

Leaves are shaped lots of different ways, and after drawing these you’ll be able to notice them more! The most common leaf shape is ovate, which is named after the latin word “ova” which means egg-shaped. The elliptical shape is symmetrical, and would look the same if you flipped it around. Obovate leaves are like ovate, just opposite, which the widest part near the tip. “Ob” means opposite, which is why it’s called obovate. Lanceolate leaves are long, skinny and look like a “lance” or a sword. Can you guess how the oblanceolate shape got its name? Stellate leaves are shaped like a star. “Stella” is the latin word for star. Cordate leaves are heart-shaped. “Cord” means of the heart. Pretty neat, huh!? 

 

Now there are a couple of things for you to know before we move on. The “leaf stalk” is the part of the leaf that connects the “base” to the “stem” of the plant. Plants that have parts that stick out are called “lobes” and parts that turn in, creating empty spaces are called “sinuses”.

 

Got it? Why don’t you try drawing all of these different shapes. 

 

Part II - Leaf Edges

 

The margin of the leaf is the edge. At first look you might not notice the edge of the leaf, but they can look very different from each other and this can help you identify a new plant!

 

The leaves we’ve draw already have “smooth” margins. Jagged edged leaves are called “serrated” or “toothed”. Leaves with two or more rows of teeth are called “souble-serrated” or “double-toothed”. Wavy edges are called undulate. Sharply wavy or scalloped edges are called “crenate”. A leaf that has tiny hairs on it is called “ciliate”. These are easy to miss, so you’ll have to look closely to spot them!

Part III - Leaf Attachment

 

Aren’t all leaves stuck to plants the same way? No, there are some interesting ways leaves are connected to the rest of the plant. Sessile leaves are attached right on the stem, with no stalk. Stalked leaves have a little stalk separating them from the stem. 

Clasping leaves partially wraps around the stem or fully encloses it like a tube or shirt sleeve. Perfoliate leaves look like the stem is cutting right through the leaf. Watch the last 30 seconds of the video again and see if you can spot the “perfoliate” leafed plant! Leaves that come directly from the ground with no stem are called basal. Dandelion is an example of this!

Part IV - Leaf Arrangement

 

Each plant arranges their leaves differently. Draw these four different ways that plants often “wear” their leaves. The “node” is the place on the stem or branch where the leaves are attached. Sometimes you can see the node because it is thicker than the other parts of the stem or the stem zigzags at these joints. If a plant has an alternate arrangement, it will have just one leaf per node. If a plant is opposite, there will be two leaves per node. Whorled plants will have more than two per node.

 

Of course, it’s not quite that simple. In our drawing each row of leaves is directly in line with the ones above and below them. On many plants, leaves come out of nodes in different positions and spiral, rather than being parallel. 

Part V - Simple or Compound Leaves

 

The leaves we’ve drawn so far are simple, with just one main leaf. Many leaves, though, are broken up into tiny leaflets that all together make up just one leaf. Clover is an example of a plant that has just one leaf, made of three leaflets (or four or more if you’re lucky). 

 

There are three types of compound leaves - pinnate, twice-pinnate, and palmate. Pinnate leaves are attached like a feather along the rachis, an extension of the main stalk (pinna is latin for feather). Twice pinnate leaves have lots of little “feathers” coming off of the rachis, and palmate leaves radiate out from one spot, looking somewhat like the “palm” of your hand.

Part VI - Veins

 

Veins are an important part of the leaf that transports water and nutrients throughout the plant. Veins can run from one point at the base of the leaf spreading outward - palmate, side by side - parallel, or spread out from different points along the central vein mid-rib - pinnate, like a feather. 

 

When determining the vein pattern or at compound leaves, pay extra attention to the leaf structure as a whole, and not the individual leaflets. For example, Buckeye leaflets are pinnately veined like a feather, but the overall compound leaf is palmate-veined since they fan out like the palm of your hand. 

Ready for adventure?

 

Whew, that was a lot! Do you have it all written down in your journal? After you do, take a good long break and then come back!

 

Once you’re rested and ready to go, take your journal with you to a plant around your home. Then go through your botany chapter and key out the different parts of your plant. If you aren’t sure about the answer to some of the questions, it’s okay! Just put down your best guess.

 

Write these down. 

 

Part I - What is your leaf shape?

Part II - What is your leaf margin? 

Part III - How is your leaf attached?

Part IV - How are the leaves on the plant arranged?

Part V - Are the leaves simple or compound?

Part VI - What is the vein pattern?

Part VII - What is the stem cross-section shape?

Part VIII - Is your leaf hairy?

Part VIIII - What is the flower shape? Can you identify all of the different parts?

Part X - Does your plant have a smell? If you rub the leaves do your fingers smell? Does it have a flower that smells?

Part XI - How many different colors and shades are on your plant? Is your plant fancy or plain? :)

 

You did it! Now pat yourself on the back and have a good long rest. If you feel inspired, try this again with one or two more plants. The more you do it, the more the language of plants will open for you!

 

Part VII - Stem Shape

 

When identifying plants it’s very helpful to notice the shape of the stem. We look extra closely at the cross-section - as if you cut the stem in half and looked down at the shape of the cut. Many people think that all stems are round, but they come in all kinds of shapes! Mint plants, for example have square stems! Draw these different shapes. 

Part VIIII - Flowers

 

If you are lucky enough to find a plant that is in flower, it can be very helpful for identification!

 

Two basic flower shapes are “Regular” and “Irregular”.

 

Regular flowers are radial, or shaped like a wheel, with petals going out from a central point. They are symmetrical, so an insect in the center of the flower will see pretty much the same shape no matter which direction it looks. A wood anemone is a good example of a regular flower.

 

Irregular flowers are symmetrical on the right and left side. If a line was drawn down the middle of the flower it would look like the two sides are mirror images of each other. This is called bilateral symmetry. 

 

*It can be tricky finding part of the flower in some plants. Sunflowers, for example, look like one big flower, but the center is actually made up of lots of tiny disk flowers. On a daisy, what looks like petals are actually complete ray flowers. If you look close, you will be able to see why! Even on dogwoods, what looks like big white petals on the flower are actually modified leaves, or bracts, and the flower is the green part in the center!

 

Petals are beautiful and often colorful, but there’s more to it! Many petal colors are not visible to the human eye, but help flying insects see where to land and pollinate the blossom. 

 

In a radial flower you will usually find a pistil at the center of the petals, which is the female part with an ovary, and is ready to receive pollen. The opening at the top is called the stigma, above the tube-like style. The stamens are clustered around it with pollen-producing anthers at the tip over a stalk called a filament. Green sepals can be found underneath the petals, which altogether are called the calyx. Some flowers, however, have only male or female parts. 

 

 

The drawings below show the parts of a flower as well as different ways that a flower can be arranged on a plant.

Part VIII - Hair

 

Plant leaves can be smooth or covered in hair. Smooth leaves are called “glabrous”, finely hairy “pubescent” or very hairy “hispid”.

Part X - Smell

 

Another thing that makes each plant unique is its smell! This can be a great way to tell a plant apart from others! When you rub Little Brown Jug leaves with your fingers they smell sweet and ginger-like, which is why it’s also considered a wild ginger. If you rub Paw Paw leaves (from Chapter II) they smell spicy like a tomato or pepper plant! Sometimes it can be hard to tell certain plants apart, but the smell can help assure you that you’ve got the one you’re looking for! Plus, it’s just plain fun to go around sniffing plants like a wild animal!

 

Part XI - Color

 

Plants have lots of different shades and colors! Sometimes you need to look closely to find them. Many plants have silvery or colorful undersides to their leaves. Silvery undersides may help reflect light so plants get a double-dose of sun! Other pigments (like the purple in Crane Fly Orchid) may act as a sunscreen so that they leaves don’t get damaged by too much sunlight on the unprotected forest floor in winter and early spring. People don’t exactly know why plants have chosen certain colors…maybe Sir Cumberbun is right and they’re just fancy!