Photo by Verne Morton.
"Whence O fragrant form of light,
Hast thou drifted through the night
Swanlike, to a leafy nest,
On the restless waves at rest."
Thus asks Father Tabb, and if the lily could answer it would have to say: "Through ages untold have the waves upheld me until my leaves and my flowers have changed into boats, my root to an anchor, and my stems to anchor-ropes."
There is no better example for teaching the relation between geography and plant life than the water lily. Here is a plant that has dwelt so long in a certain situation that it cannot live elsewhere. The conditions which it demands are quiet water, not too deep, and with silt bottom. Every part of the plant relies upon these conditions. The rootstock has but few root hairs; and it lies buried in the silt, not only because this gives it food, but because it can there act as an anchor. Rising from the rootstock is a stem as pliable as if made of rubber, and yet it is strong; its strength and flexibility are gained by having at its center four hollow tubular channels, and smaller channels near the outside. These tubes extend the whole length of the stem, making it light so that it will float, and at the same time giving it strength as well as flexibility. At the upper end of the stem is a leaf or flower, which is fashioned as a boat. The circular leaf is leathery and often bronze-red below, with prominent veins, making an excellent bottom to the boat; above, it is green with a polished surface, and here are situated its breathing-pores, although the leaves of most plants have these stomata in the lower surface. But how could the water lily leaf breathe, if its stomata opened in the water? The leaf is large, circular and quite heavy; it would require a very strong, stiff stem to hold it aloft, but by its form and structure it is fitted to float upon the water, a little green dory, varnished inside, and waterproof outside.
The bud is a little, egg-shaped buoy protected by its four pinkish brown, leathery sepals; as it opens, we can see four rows of petals, each overlapping the space between the next inner ones; at the center there is a fine display of brilliant yellow anthers. Those hanging over the greenish yellow pit, which has the stigma at its center, are merely golden hooks. When the flower is quite open, the four sepals, each a canoe in form, lie under the lily and float it; although the sepals are brownish outside, they are soft white on the inside next the flower. Between each two sepals stands a large petal, also canoe-shaped, and perhaps pinkish on the outside; these help the sepals in floating the flower. Inside of these there is a row of large creamy white petals which stand upright; the succeeding rows of petals are smaller toward the center and grade into the outer rows of stamens, which are petallike at the base and pointed at the tip. The inner rows of stamens make a fine golden fringe around the cup-shaped pistil. This flower is of great use in teaching that sepals, petals and stamens have the same origin and grade into each other, showing the intermediate stages.
Egyptian lotus flower and seed-vessel.
It has been stated that pond lilies, in the state of nature, have an interesting way of opening in the early morning, closing at noon and opening again toward evening. If we knew better the habits of the insects which pollenate these flowers, we should possibly have the key to this action. In our ponds in parks and grounds we find that each species of pond lily opens and closes at its own particular time each day. Each flower opens usually for several consecutive days, and the first day of its blooming it opens about an hour later and closes an hour earlier than on the days following. After the lilies have blossomed, the flower stem coils in a spiral and brings the ripening seeds below the surface of the water. The reason for this has not yet been discovered. After about two months the pod bursts letting the seeds out in the water. Each seed is in a little bag, which the botanists call an aril, and which serves as a life preserver floating the seed off for some distance from the parent plant. The aril finally decays and the seed falls to the bottom where, if the conditions are favorable, it develops into a new plant.
Seed vessel of white pond lily.
To emphasize the fact that the water lily is dependent upon certain geographical conditions, ask the pupils to imagine a water lily planted upon a hillside. How could its roots, furnished with such insufficient rootlets, get nourishment there? How could its soft, flexible stems hold aloft the heavy leaves and blossoms to the sunlight? In such a situation it would be a mere drooping mass. Moreover, if the pupils understand the conditions in which the water lilies grow in their own neighborhood, they can understand the conditions under which the plant grows in other countries. Thus, when they read about the great Victoria regia of the Amazon,—that water lily whose leaves are large enough to support a man,—they would have visions of broad stretches of still water and they should realize that the bottom must be silt. If they read about the lotus of Egypt, then they should see the Nile as a river with borders of still water and with bottom of silt. Thus, from the conditions near at hand, we may cultivate in the child an intelligent geographical imagination.
Leading thought—The water lily has become dependent upon certain conditions in pond or stream, and has become unfitted in form to live elsewhere. It must have quiet waters, not too deep, and with silt bottom.
Method—The study should be made first with the water lilies in a stream or pond, to discover just how they grow. For the special structure, the leaves and flowers may be brought to the schoolroom and floated in a pan of water. The lesson may easily be modified to fit the yellow water lily, which is in many ways even more interesting, since in shallow water it holds its leaves erect while in deeper water its leaves float.
1. Where is the water lily found? If in a pond, how deep is the water? If in a stream, is it in the current? What kind of bottom is there to the stream or pond? Do you find lilies in the water of a limestone region? Why?
2. What is the shape of the leaf? What is the color above and below? What is the texture? How is it especially fitted to float? How does it look when very young?
3. Examine the petiole. How long is it? Is it stiff enough to hold up the leaf? Why does it not need to hold up the leaf? How does it serve as an anchor? Cut a stem across and describe its inside structure. How does this structure help it float?
4. Examine the open flower. How many sepals? How many rows of petals? How do the stamens resemble the petals? Can you see in the water lily how the sepals, petals and stamens may all be different forms of the same thing? How are the sepals fitted to keep the flower afloat? At what times of the day does the lily open? At what hours does it close?
5. Describe the pistil. When the lily first opens, how are the stamens placed around the pistil? What happens to the seed-box after the blossoms have faded? Does the seed-pod float upon the water as did the flower? What sort of stem has the flower? How does this stem hold the seed-pod below the water?
6. What sort of seed has the water lily? Sketch the seed-pod. How does the seed escape from it? How is it scattered and planted?
7. What sort of a root has the water lily? Are there many fine rootlets upon it? Why? How does this rootstock serve the plant aside from getting food?
8. Imagine a water lily set on a dry hillside. Could the stems uphold the flowers or leaves? Is the petiole large enough to hold out such a thick, heavy leaf? Could the root get food from a dry location? Why?
9. Judging from what you know of the places where water lilies grow and the condition of the water there, describe the Nile where the lotus grows. Describe the Amazon where the Victoria regia grows.