Anna B. Comstock

How an Apple Grows

Teacher's Story

An apple tree in full blossom is a beautiful sight. If we try to analyze its beauty we find that on the tip of each twig there is a cluster of blossoms, and set around them, as in a conventional bouquet, are the pale, soft, downy leaves. These leaves and blossoms come from the terminal winter buds, which are protected during winter by little scales which are more or less downy. With the bursting of the bud, these scales fall off, each one leaving its mark crosswise on the twig, marking the end of the year's growth; these little ridges close together and in groups mark the winters which the twig has experienced, and thus reveal its age.

There is a difference in varieties of apples and in the season as to whether the blossoms or the leaves push out first. The white, downy leaves at first have two narrow stipules at the base of their petioles. They are soft, whitish and fuzzy, as are also the flower stem and the calyx, which holds fast in its slender, pointed lobes the globular flower bud. We speak of the lobes of the calyx because they are joined at the base, and are not entirely separate as are sepals. The basal part of the calyx is cup-shaped, and upon its rim are set the large, oval petals, each narrowing to a slender stem at its base. The petals are set between the sepals or lobes of the calyx, the latter appearing as a beautiful, pale green, five-pointed star at the bottom of the flower. The petals are pink on the outside and white on the inside, and are veined from base to edge like a leaf; they are crumpled more than are the cherry petals.

The many pale, greenish white stamens of different lengths and heights stand up like a column at the center of the flower. They are tipped with pale yellow anthers, and are attached to the rim of the calyx-cup. They are really attached in ten different groups but this is not easy to see.

The five pale green styles are very silky and downy and are tipped with green stigmas. The pistils all unite at their bases making a five-lobed, compound ovary. The upper part of this ovary may be seen above the calyx-cup, but the lower portion is grown fast to it and is hidden within it. The calyx-cup is what develops into the pulp of the apple, and each of these pistils becomes one of the five cells in the apple core. If one of the stigmas does not receive pollen, its ovary will develop no seed; this often makes the apple lop-sided. When the petals first fall, the calyx-lobes are spread wide apart; later they close in toward the center, making a tube. To note exactly the time of this change is important, since the time of spraying for the codling moth is before the calyx-lobes close. These lobes may be seen in any ripe apple as five little, wrinkled scales at the blossom end; within them may be seen the dried and wrinkled stamens, and within the circle of stamens, the sere and blackened styles.

Just ready to spray.   A pear and two apples from which the petals have recently fallen and with calyx lobes widely spread.  Photo by M. V. Slingerland.

There may be five or six, or even more blossoms developed from one winter bud, and there may be as many leaves encircling them, forming a bouquet at the tip of the twig. However, rarely more than two of these blossoms develop into fruit, and the fruit is much better when only one blossom of the bouquet produces an apple; if a tree bears too many apples it cannot perfect them.

The blossoms and fruit are always at the end of the twigs and spurs of the apple tree, and do not grow along the sides of the branches as do the cherry and the peach. However, there are many buds which produce only leaves; and just at the side and below the spur, where the apple is borne, a bud is developed, which pushes on and continues the growth of the twig, and will in turn be a spur and bear blossoms the following year.

Method—This lesson should begin with the apple blossoms in the spring and should continue, with occasional observations, until the apples are well grown. If this is not possible, the blossom may be studied, and directly afterward, the apple may be observed carefully, noting its relation to the blossom.

Apple blossoms.  Photo by Verne Morton.

2. As the winter buds open, which appear first—the flowers or the leaves? Do they both come from the same bud? Do all the buds produce both flowers and leaves?

3. Study the bud of the apple blossom. Describe its stem; its stipules; its calyx. What is the shape and position of the lobes, or sepals, of the calyx? Why do we usually call them the "lobes of the calyx" instead of sepals?

4. Sketch or describe an open apple blossom. How many petals? What is their shape and arrangement? Can you see the calyx-lobes between the petals as you look down into the blossom? What sort of a figure do they make? Are the petals usually cup-shaped? What is their color outside and inside? Why do the buds seem so pink and the blossoms so white?

5. How many stamens are there? Are they all of the same length? What is the color of the filaments and anthers? On what are they set?

6. How many pistils do you see? How many stigmas are there? Are the ovaries united? Are they attached to the calyx?

7. Describe the young leaves as they appear around the blossoms. What is their color? Have they any stipules? Why do they make the flowers look like a bouquet?

8. After the petals fall, what of the blossom remains? What part develops into the apple? Does this part enclose the ovaries of the pistils? How can you tell in the ripe apple if any stigma failed to receive pollen?

9. What is the position of the calyx-lobes directly after the petals fall? Do they change later? How does this affect spraying for the codling moth?

10. Watch an apple develop; look at it once a week and tell what parts of the blossom remain with the apple.

11. How many blossoms come from one winter bud? How many leaves? Do the blossoms ever appear along the sides of the branches, as in the cherries? How many blossoms from a single bud develop into apples?

12. Since the apple is developed on the tip of the twig how does the twig keep on growing?

13. Compare the apple with the pear, the plum, the cherry and the peach in the following particulars: position on the twigs; number of petals; number and color of stamens; number of pistils; whether the pistils are attached to the calyx-cup at the base.