Plant Nature Study I by Various Plant Nature Study I by Various    

Lesson 21: Beautiful Mischievous Cousins (Defensive Mechanisms)

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Peter found no more new flowers in the Old Pasture the day he found the Lupine, and it was some time before he went back there again. June, the first of the summer months, had come. The Pasture Rose bushes were now a mass of beautiful pink blossoms. Where Peter had found the first Lupine in bloom the ground was now blue with them. Parts of the Green Meadows were yellow with Buttercups and other parts were white with Daisies. It seemed as if everywhere there were flowers, for June is of all months the month of flowers.

Following an old cow path up through the Old Pasture, Peter came to a rocky hillside where grew little and big bushes, sometimes singly and sometimes in masses. The leaves were long, oval, smooth and thick. The older ones were a dark green, the new ones being lighter. All winter those older leaves had remained green. Peter knew all about them. They were leaves that he never tasted, not even when the snow was so deep that he had hard work to find anything to eat. Those leaves were poisonous, and Peter knew enough to let them alone. In this he was wiser than some sheep and cattle, many of which are killed every year by eating these tempting-looking leaves.

But Peter gave no thought to those leaves. You see those bushes were covered with great masses of white and delicate pink blossoms. They grew in great clusters, and it seemed to Peter that never had he seen anything more beautiful. One of these bushes was no higher than Peter's head, and he could look at those blossoms as closely as he pleased.

Each flower was an inch or less across, and was shaped like a tiny bowl with five low points. Around the middle on the outside were ten little projections which on the inside formed ten very tiny pockets. Inside, starting from the center, were ten white stamens, but these stamens, instead of standing straight up as do the stamens in most flowers, were bent over like a spring, and the anther, which you know is the little package of pollen at the end of each, was held fast in one of those little pockets I have mentioned. Standing straight up in the middle was a single pale green pistil.

Peter was so used to seeing the pollen-covered anthers on the tips of the stamens in other flowers that he missed them in this one. You see, when he first saw those bent-over stamens he didn't recognize them as stamens at all. But presently a Bee came along and entered the flower Peter was looking at. Then surprising things happened. She touched one of those bent-over stamens and instantly it straightened up like a spring, bringing with it the little anther which had been held in one of those tiny pockets and had kept the stamen bent over. The sudden springing up of that stamen caused the little anther on its tip to throw a shower of golden pollen on that Bee. You see it was a regular little spring gun. One after another the other stamens did the same thing as the Bee touched them.

Then Peter understood. Old Mother Nature had given this flower these tiny spring guns to make sure that whoever visited them should carry away pollen to leave in the next flower entered. Peter watched that Bee leave that flower and go to another, where of course the same thing happened. The first time he had exclaimed right out because he was so surprised. Even after he had seen a dozen of those little spring guns go off he had that same feeling of surprise each time.

When the Bee had flown away, Peter sat there for a long time hoping that she or another would come back so that he might see more of those little spring guns go off. Finally he ventured to touch one of those blossoms and found that by so doing he could make those little stamens spring up and throw their tiny showers of golden dust. It was great fun. While doing this he discovered that the stems were sticky.

"I wonder why that is," said Peter to himself, but of course he couldn't answer it himself and there was no one there to tell. Had Old Mother Nature happened along she might have explained to him that it prevented ants and other crawling insects from getting into those flowers. These insects would not carry the pollen from flower to flower as the Bees do.

Perhaps you have guessed what flower it was Peter had found. It was a flower with several names, its most familiar ones being American Laurel and Mountain Laurel. It is also called Calico Bush, Clamoun, Kalmia and Spoonwood. The wood of the Laurel is very hard, and has been much used for making wooden spoons. Of course this is why it is called Spoonwood in some places.

Just before Peter left to go in search of other flowers he discovered a beautiful Swallow-tail Butterfly laying eggs on one of the Laurel leaves. He knew enough about Butterflies to know that they lay their eggs where the caterpillars hatching from them will find food right at hand. This meant that the caterpillars which would come from these eggs would eat the Laurel leaves, and that therefore they could not be poisonous to them as they are to animals.

Peter had gone but a short way when he came to a little bush which he knew at once to be a little cousin of the Mountain Laurel. "The Lambkill is in bloom!" he cried, and eagerly hurried forward to see if this also had those funny little spring guns.

Just as the plant was very much smaller than its big cousin so were the flowers much smaller. They grew in a big cluster around the stem, while the flowers of the Mountain Laurel were at the end of the stem. Standing straight up above each cluster of flowers was the new growth of the year, its leaves reaching straight up, while the old leaves drooped downward. The new leaves were light green, while the old leaves were dark. In shape they were much like those of the Mountain Laurel, but of course much smaller and also narrower.

But the flowers themselves were formed like little Laurel blossoms, and to Peter's joy he found that they also contained the little spring guns. In color they were a deep pink, and the stamens and pistils also were pink. Peter knew this plant well and not for the world would he have eaten one of those leaves. He knew it to be even more poisonous than the leaves of the Mountain Laurel. That is why it is often called Lambkill and Calfkill and Sheep Poison. Many foolish sheep and young cattle have died because of eating it. It is also called Sheep Laurel and Wicky.

When Peter left the Sheep Laurel he followed an old cow path that led up to the top of the Old Pasture where it joined the foot of the Great Mountain. There one more surprise greeted him just within the edge of the woods. It was almost big enough to be called a small tree. Had Peter been living farther south he might have found some of these plants so large that they really were trees.

One glance at the leaves was enough for Peter to know that here was another cousin of the Mountain Laurel. They were larger and broader than the Mountain Laurel leaves, and a darker green, but in shape and appearance were much the same.

But Peter had eyes only for the wonderful great clusters of beautiful flowers, some of the flowers being almost two inches across. Some were a wonderful soft pink, while others were almost white and were bell-shaped, and as Peter looked up at them appeared to have five petals. Of course the first thing he looked for was to see if these beautiful blossoms also had those wonderful little spring guns. He was disappointed. They didn't have. There were ten stamens, but they stood upright instead of being bent over like little springs.

Peter had found one of the most beautiful of all our wild flowers, the American or Great Rhododendron, also called Great Laurel, Rose Tree or Bay.

    Plant Nature Study I by Various Plant Nature Study I by Various    

Lesson 21: Beautiful Mischievous Cousins (Defensive Mechanisms)

Directions

Study the lesson for one week.

Over the week:

  • Read the story.
  • Review the synopsis.
  • Recite aloud the vocabulary words and their definitions.
  • Learn the concepts.
  • Complete the enrichment activities.
  • Study the review questions.

Synopsis

Peter finds Mountain Laurel bushes covered in white and pink delicate blossoms. He does not eat the leaves, which are poisonous and kill many sheep and cattle every year when eaten. Each bowl-shaped flower has ten stamens bent down and tucked into ten pockets running along the perimeter of the bowl. Peter sees a bee enter one of the bowls and touch a bent stamen. The stamen springs up from its pocket and showers the Bee with pollen. Peter realizes the stamens are like little spring guns. The stem of these flowers is sticky, preventing ants from climbing into the flowers and getting the pollen, for the ants do not carry pollen from flower to flower. Peter next finds the Lambkill, a cousin of the Mountain Laurel. The Lambkill has smaller, deep-pink bowl-shaped blossoms with little spring gun stamens like their cousin. The Lambkill is even more poisonous than the Mountain Laurel, hence its name. Peter next finds the American or Great Rhododendron, another cousin of the Mountain Laurel. The blossoms were white and beautiful, but Peter is disappointed to find that they had no spring gun stamens.

Vocabulary

Defensive: Intended to protect or to deter attack.
Mechanism: A natural, mental, physical, or chemical process by which something happens.
Perimeter: The outer limits of an area.
Spring Gun: A gun rigged to fire when a string is tripped.

Concepts

Plant Defensive Mechanisms:

  1. Although plants have no brains, sharp claws, or pointy teeth, some are dangerous to other living things.
  2. Plants often protect themselves from being eaten or from having their pollen or nectar stolen by animals who do not help with cross-pollination.
  3. In the story, Peter discovers Mountain Laurels have sticky stems to prevent ants from stealing their pollen.
  4. Peter also knows not to eat the poisonous leaves of the Mountain Laurel or Lambkill, which kill many sheep and cattle.
  5. Plants have many types of defensive mechanisms such sticky stems, poison, bitter tastes, thorns, prickles, and spines.
  6. Which type of defensive mechanism do you see on the cacti?

Enrichment

Activity 1: Narrate the Story

  • After reading or listening to the story, narrate the story events aloud using your own words.

Activity 2: Can You Find It?

Review the following flower parts on the diagram of the flower and relate them to the parts of the Mountain Laurel. Point to the part that:

  • Is like a spring gun in the Mountain Laurel.
  • Stands up straight and green from the middle of a Mountain Laurel blossom.
  • Is shaped like a bowl in the Mountain Laurel.
  • Is tucked into pockets in the Mountain Laurel.
  • Is sticky to prevent ants from getting the Mountain Laurel's pollen.

Activity 3: Continue Your Experiment - Which Amount of Light is Best for Beans?

  • Continue to water the seeds. Keep the soil damp over the duration of the experiment.
  • Complete your fourth week of observations of the bean seeds.
  • Which seeds have growing well? Which seeds are doing poorly?
  • Use the gathered information to create a final field book entry on your experiment.

Activity 4: Complete a Field Book Entry   

As you conduct your experiment, complete page 26 in 'Science Field Book for Third Grade.'

Review

Question 1

You see your dog sniffing at the leaves of a Mountain Laurel. Should you pull your dog away?
1 / 6

Answer 1

Yes, you should pull your dog away. The leaves of the Mountain Laurel are poisonous.
1 / 6

Question 2

How are the stamens of the Mountain Laurel like a spring gun?
2 / 6

Answer 2

When an insect touches a Mountain Laurel stamen, the stamen springs up from its pocket.
2 / 6

Question 3

How is a spring-loaded stamen advantageous to the Mountain Laurel?
3 / 6

Answer 3

A spring-loaded stamen helps the Mountain Laurel reproduce, because it showers pollinators with pollen.
3 / 6

Question 4

Give two examples of defensive mechanisms of plants.
4 / 6

Answer 4

Defensive mechanisms listed might include sticky stems, poison, bitter tastes, thorns, prickles, and spines.
4 / 6

Question 5

What defensive mechanism do cacti have?
5 / 6

Answer 5

Cacti have spines that protect the plant from being eaten.
5 / 6

Question 6

Describe the meaning of the name of the lambkill plant.
6 / 6

Answer 6

The lambkill gets its name because sheep die when they eat the plant.
6 / 6

  1. You see your dog sniffing at the leaves of a Mountain Laurel. Should you pull your dog away? Yes, you should pull your dog away. The leaves of the Mountain Laurel are poisonous.
  2. How are the stamens of the Mountain Laurel like a spring gun? When an insect touches a Mountain Laurel stamen, the stamen springs up from its pocket.
  3. How is a spring-loaded stamen advantageous to the Mountain Laurel? A spring-loaded stamen helps the Mountain Laurel reproduce, because it showers pollinators with pollen.
  4. Give two examples of defensive mechanisms of plants. Defensive mechanisms listed might include sticky stems, poison, bitter tastes, thorns, prickles, and spines.
  5. What defensive mechanism do cacti have? Cacti have spines that protect the plant from being eaten.
  6. Describe the meaning of the name of the lambkill plant. The lambkill gets its name because sheep die when they eat the plant.

References

  1. 'Cactus Flowerpot Sting by ulleo. {(CC0 1.0)}' Pixabay. pixabay.com/en/cactus-flowerpot-plant-sting-2117102/. n.p.
  2. Burgess, Thornton. Burgess Flower Book for Children. Ithaca, Boston, Massachusetts. Little, Brown, and Company, 1923.
  3. Comstock, Anna Botsford and Gordon, Eva L., Handbook of nature-study (Twenty-fourth edition). Ithaca, New York Comstock Publishing Company, Inc, 1911.