Anna B. Comstock

The Horse-Chestnut

Teacher's Story

HE wealth of children is, after all, the truest wealth in this world; and the horse-chestnuts, brown and smooth, looking so appetizing and so belying their looks, have been used from time immemorial by boys as legal tender—a fit use, for these handsome nuts seem coined purposely for boys' pockets.

The horse-chestnut is a native of Asia Minor. It has also a home in the high mountains of Greece. In America, it is essentially a shade tree. Its head is a broad cone, its dark green foliage is dense and, when in blossom, the flower clusters stand out like little white pyramids against the rich back-ground in a most striking fashion. "A pyramid of green supporting a thousand pyramids of white" is a clever description of this tree's blossoming. The brown bark of the trunk has a tendency to break into plates, and the trunk is just high enough to make a fitting base for the handsome head.

a, blossom of the sweet buck-eye and young fruit; b, blossom and young fruit of horse-chestnut.

The blossom panicle is at the tip end of the twig and stops its growth at that point; the side buds continue to grow thus making a forking branch. Each blossom panicle stands erect like a candle flame, and the flowers are arranged spirally around the central stem, each pedicel carrying from four to six flowers. The calyx has five unequal lobes, and it and the stem are downy. Five spreading and unequal petals with ruffled margins are raised on short claws, to form the corolla; seven stamens with orange colored anthers are thrust far out and up from the flower. The blossoms are creamy or pinkish white and have purple or yellow blotches in their throats. Not all the flowers have perfect pistils. The stigmas ripen before the pollen, and are often thrust forth from the unopened flower. The flowers are fragrant and are eagerly visited by bumblebees, honey-bees and wasps.

Horse-chestnut blossoms. Photo by Verne Morton.

Very soon after the blossom falls, there may be seen one or two green, prickly balls which are all the fruits one flower cluster could afford to mature. By October the green, spherical husk breaks open in three parts, showing its white satin lining and the roundish, shining, smooth nut at its center. At first there were six little nuts in this husk, but all except one gave up to the burly occupant. The great, round, pale scar on the nut is where it joined the husk. Very few American animals will eat the nut; the squirrels scorn it and horses surely disown it.

In winter, the horse-chestnut twig has at its tip a large bud and looks like a knobbed antenna thrust forth to test the safety of the neighborhood. There are, besides the great varnished buds at the ends of the twigs, smaller buds opposite to each other along the sides of the twig, standing out stiffly. On each side of the end bud, and below each of the others, is a horseshoe-shaped scar left by the falling leaf of last year. The "nails" in this horseshoe are formed by the leafy fibers which joined the petiole to the twig. The great terminal buds hold both leaves and flowers. The buds in winter are brown and shining as if varnished; when they begin to swell, they open, displaying the silky gray floss which swaddles the tiny leaves. The leaves unfold rapidly and lift up their green leaflets, looking like partly opened umbrellas, and giving the tree a very downy appearance, which Lowell so well describes:

The leaf, when fully developed, has seven leaflets, of which the central ones are the larger. They are all attached around the tip of the petiole. The number of leaflets may vary from three to nine, but is usually seven. The leaflets are oval in shape, being attached to the petiole at the smaller end; their edges are irregularly toothed. The veins are large, straight and lighter in color; the upper surface is smooth and dark green, the under side is lighter in color and slightly rough. The petiole is long and shining and enlarges at both ends; when cut across, it shows a woody outer part encasing a bundle of fibers, one fiber to each leaflet. The places where these fibers were attached to the twig make the nails in the horseshoe scar. The leaves are placed opposite on the twigs.

Very different from that of the horse-chestnut is the flower of the yellow or sweet, buckeye; the calyx is tubular, long and five-lobed; the two side petals are on long stalks and are closed like spoons over the stamens and anthers; the two upper petals are also on long stalks, lifting themselves up and showing on their inner surfaces a bit of color to tell the wandering bee that here is a tube to be explored. The flowers are greenish yellow. The flowers of the Ohio buckeye show a stage between the sweet buckeye and the horse-chestnut. The Ohio buckeye is our most common native relative of the horse-chestnut. Its leaves have five leaflets instead of seven. The Sweet buckeye is also an American species and grows in the Alleghany mountains.

Method—This tree is almost always at hand for the village teacher, as it is so often used as a shade tree. Watching the leaves develop from the buds is one of the most common of the nature-study lessons. The study of the buds, leaves and fruits may be made in school; but the children should observe the tree where it grows and pay special attention to its insect visitors when it is in bloom.

2. Study the blossom cluster; are the flowers borne on the ends or on the sides of the twig? Describe the shape of the cluster. How are the flowers arranged on the main flower stalk to produce this form? Do the flowers open all at once from top to bottom of the cluster? Are all the flowers in the cluster the same color? Are they fragrant? What insects visit them?

Horse-chestnuts, the coin of the small boy. Photo by O. L. Foster.

3. Take a single flower; describe the form of the calyx. Is it smooth or downy? Are the lobes all the same size? Are the petals all alike in size and shape? What gives them the appearance of Japanese paper? Are any connected together? Are they all splashed with color alike?

4. How many stamens are there? Where do you see them? What color are the anthers? Search the center of a flower for a pistil with its green style. Do you find one in every flower? Could a bee reach the nectar at the base of the blossom without touching the stigma? Could she withdraw without dusting herself with pollen?

5. How long after the blossom does the young fruit appear? How does it look? How many nuts are developed from each cluster of blossoms? What is the shape of the bur? Into how many parts does it open? Describe the outside; the inside. Describe the shape of the nuts, their color and markings. Which make the best "conquerors," those which grow single in the bur or as twins? Open a nut. Can you find any division in the kernel? Is it good to eat?

7. Describe the scars below the buds. What caused them? What marks are on them? What made the "nails" in the horseshoe? Has the twig other scars? How do the ring-marks show the age of the twig? Do you see the little, light colored dots scattered over the bark of the twig? What are they?

8. Describe how the leaf unfolds from the bud. What is the shape of the leaf? Do all the leaves have the same number of leaflets? Do any of them have an even number? How are the leaflets set upon the petiole? Describe the leaflets, including shape, veins, edges, color above and below. Is the petiole pliant, or stiff and strong? Is it the same shape and size throughout its length? Break a petiole, is it green throughout? What can you see at its center? Are the leaves opposite or alternate? When they fall, do they drop entire or do the leaflets fall apart from the stem?

9. Sketch the horse-chestnut tree.

10. How do the flowers and leaves of the horse-chestnut differ from those of the sweet buckeye and of the Ohio buckeye?

Supplementary reading—Trees in Prose and Poetry, p. 17.