Have you taken a good look at drawings of modern rockets? These are miracles of engineering; each piece is there for a purpose, and nothing may be left off, nothing non-functional added. When it is built, this machine, designed with sheer function in mind, has a grim beauty about it.
And so with plants, they have evolved, undergone structural changes to meet changing environments, altered their biochemical systems, and are still strictly functional. So functional are plants that scientists can come nowhere near making one.
Parenthetically, however, we must doff our hats to the hybridizers who give short shrift to nature’s streamlining as they enlarge blossoms, brighten colors, and increase the number of petals.
What Is A Flowering Plant?
What is a flowering plant, exactly? Well, it is a thing with a flower on one end, a root on the other, and sonic stems and leaves in between.
Which part is most important? From the gardener’s standpoint, probably the blossom.
From the cow’s standpoint, the leafy parts. To mother nature, it is the seeds that the flower will produce, assuring more of the same variety next year so that the meadow will remain in balance.
We can see, too, that a flowering plant is arranged on a longitudinal axis, sometimes branched, but with roots at the lower end, stems supporting the foliage, and flowers at the upper. It is this axis that we wish to consider.
When a seed germinates, a root appears, then a shoot, to become the stem, leaves, and, much later, the blossoms.
Why is the root first? Remember, this is a living thing, taking in oxygen to change carbohydrates to energy for growth and giving off carbon dioxide (just as people do).
The seedling must obtain water from its environment since new cells are rapidly made, and their tissues are largely water. The root goes to work gathering water from the very beginning.
As the seedling grows, using food stored in the seed and getting water and minerals from the soil using its root, it breaks out of the ground, and a shift in nutrition occurs.
As The Young Plant Reaches Light, It Turns Green
This is because it develops a green pigment, chlorophyll, within its cells. Now the plant can perform a function that is unique to the plant kingdom. It can make its food.
Have you ever thought about where your energy comes from?
We eat plants, plant products, or animals. Those animals were pastured or fed corn or hay, so eventually, we returned to plants as a source of our food energy.
As for heat or light–that, too, probably comes from coal, petroleum, or methane gas, underground deposits of organic chemicals that started with plants long ago.
Only hydroelectric power or solar cells can supply us with energy that does not involve plants.
This unique function of plants is photosynthesis, a topic for a later chapter, but important to us now in talking about the longitudinal axis of the plant we are growing.
As The Young Flowering Plant Unfolds
So our young flowering plant unfolds. An active, microscopic cluster of cells at the tip of each root produces more root cells, so the roots grow forward, reaching deeper into new sources of food and water.
At the stem end, there is a similar clump of cells, always dividing, so the plant grows from the tip upward.
It is amazing how many people believe that a mark placed on a tree 10′ feet up will be much higher 20 years later. Plants do not grow that way. They grow from both ends.
It leaves behind tiny leaves that soon fill up with water and expand to full-sized foliage. There is more chlorophyll within these leaves, which are made like a photocell with many flat surfaces exposed to light.
An ever-increasing amount of photosynthesis takes place. Photosynthesis (foto-SIN-the-sis) is the name given to a complex process by which a plant can make sugar out of carbon dioxide and water, using energy from sunlight. Much of the energy used by man comes from this source.
Flowering Plant Theme
We can now enlarge our theme of what a flowering plant is. It is a system of complex parts, each dependent on the others, but, taken as a whole, it is autotrophic. That is, it can manufacture its food.
The root is responsible for water and mineral uptake, the upper parts’ physical support, and sometimes food storage.
The shoot, including everything above ground, consists of the stem (chiefly a pipeline carrying water and minerals up and foods down), leaves (at work in photosynthetic activities), and the blossoms destined to produce the seeds that will keep the species alive.
44659 by Dr. John P. Baumgardt