Peter Rabbit sat on the bank of the Smiling Pool, thinking, and, as he thought, he talked to himself, which is a way he has when he thinks he is alone. "It is a strange thing how a fellow can see a thing day after day and not really see it at all," said Peter. "Now every summer since I can remember I have seen the Wild Carrot and the Great Mullein, yet until yesterday I didn't realize that the former is beautiful, and didn't know that the blossoms of the latter open for only one day."

"Chug-arum! There's nothing strange about it, Peter Rabbit. It is always the way with people who do not use their eyes," said a gruff voice.

"Hello, Grandfather Frog!" exclaimed Peter. "I didn't see you at all. I thought I was all alone."

"Chug-arum! That goes to prove what I have just said; you do not use your eyes," retorted Grandfather Frog. "I have been sitting here on this big, green lily pad ever since you arrived. What flower did you say opens for one day only?"

"The Great Mullein," replied Peter. "The flower is yellow and quite large, but it blooms for one day only. Don't you think that is strange?"

"No, I don't," replied Grandfather Frog gruffly. "I am used to flowers that bloom only for a day."

At that Peter's long ears pricked up quickly, you may be sure. "What flowers?" he demanded eagerly. "Tell me, Grandfather Frog, what flowers do you know that open only for a day?"

Grandfather Frog opened his big mouth and laughed. At the same time he rolled his big goggly eyes up at Peter with a funny twinkle in them. "What are those two eyes of yours for, anyway, Peter Rabbit?" he demanded. "You have been looking right at those flowers ever since you sat there, yet you haven't seen them."

Peter rubbed his eyes and rather foolishly stared all about him on the bank of the Smiling Pool. Then he looked down at Grandfather Frog and opened his mouth to demand rather sharply what Grandfather Frog meant. But he closed it without saying a word, for there, just to the right of the big green lily pad on which Grandfather Frog sat, was a spike of bright blue flowers a foot above the water. Of course, they had been there all the time, yet until that instant Peter hadn't seen them at all. You see, he hadn't thought of finding flowers in the Smiling Pool, and he had been so busy thinking of other flowers that he had looked right at these without seeing them at all.

Grandfather Frog laughed again at the foolish look on Peter's face. Peter laughed too. He had to. "Of course you mean those ragged-looking little blue flowers over there," said he. "Is it really true that they bloom only for one day?"

Grandfather Frog nodded. "All those that you see today will be gone tomorrow," said he. "But there will be plenty more to take their places," he added.

Peter hopped a little closer to the water that he might see better. The flowers were very small in the form of little tubes opening out into six petal-like parts not all of the same size, which gave them rather a ragged look. Each little flower was wholly blue, even the stamens and pistil. They grew on a long spike at the end of a large, smooth, stout stem. From halfway up the stem or stalk grew out a single, large, arrow-shaped, rather thick, glossy leaf of dark green. Could Peter have gotten near enough to smell of the flowers, he would have turned up his wobbly little nose, for the scent is not at all pleasant.

"What do you call it?" asked Peter.

"The Pickerel Weed," replied Grandfather Frog. "At least, that is what I have always heard it called. I believe Pickerel are supposed to lay their eggs under its leaves, but they do that quite as much under the leaves of other water plants, so I guess there isn't any real reason for this name. However, I suppose one name is as good as another. There is one thing I like about this plant and that is that it keeps blooming all summer. That spike keeps growing longer and longer, and every day new flowers open."

"I'm ever so glad I came over here this morning," said Peter. "I hadn't thought of looking in the Smiling Pool for flowers since the Pond Lilies began to bloom. I don't suppose there are any more here."

"Yes, there are," replied Grandfather Frog. "If you will go up around that little bend you will find a wholly different flower growing in the water close to the shore."

Peter could hardly wait to thank Grandfather Frog properly, he was in such a hurry to see this new flower. He hurried along the bank around the bend, and there, sure enough, in a little cove were flowers wholly different from those he had left. While most of the plants bearing these flowers were growing in the water, a few were not in the water at all, but growing out of the mud at the water's edge. This gave Peter a chance to get as close to them as he pleased.

All the leaves of the plants not in the water were shaped like the head of an arrow. Some were quite narrow and sharply pointed, while others were broader and had more rounded points. But all were of the arrowhead shape. They were rather rubbery and in color a dark green. Looking from those plants on shore to those growing well out in the water, Peter made a surprising discovery. Those in the water had two kinds of leaves! Yes, sir, they had two kinds of leaves! The leaves standing above the water were like those of the plants on shore, but growing beneath the surface of the water were leaves entirely different. These were long and narrow, quite grass-like.

But of course it was the flowers in which Peter was most interested. These were in groups of three along a fairly tall stalk. On some plants the stalks were slender, while on others they were rather stout. The flowers were quite large, being an inch or more across. Each had three sepals and three spreading, rounded, white petals. Each flower grew out from the stalk on a short stem.

Again Peter made a surprising discovery. On some plants the flowers had a cluster of many yellow stamens in the center of each. On other plants the flowers had no pretty yellow centers, for there were no stamens at all. Instead the centers were of green pistils. Those with the stamens had no pistils at all. And then Peter found several plants with both kinds of flowers on the same stalk. Those with yellow centers were the upper flowers, while those lower down on the stalk had the green centers. Of course the yellow-centered flowers, the ones with the stamens, were the prettiest. At least Peter thought so, and I think you would agree with him.

While Peter was still admiring them, who should come stalking along but Longlegs the Great Blue Heron. "What are you doing here, Mr. Curiosity?" Longlegs asked.

"Wondering what flowers these are. Do you know?" replied Peter.

"Of course I know. It would be funny if I didn't. I supposed everybody knew them," declared Longlegs.

"I don't," said Peter honestly. "What are they called?"

"The Arrowhead, the Broad-leaved Arrowhead," replied Longlegs.

"It is a good name, a very good name," declared Peter, looking at the leaves. "One has only to look at one of these leaves to remember it. My, but it is getting late and I must hurry home! I'm much obliged to you, Longlegs."

"Don't mention it," replied Longlegs, as Peter started off lipperty-lipperty-lip.