eGarden © 2005 Ed Mues

From The Garden of Ed. Submitted for publication in The Towne Crier on May 18, 2005

The Force That Through the Green Fuse Drives the Flower #3

... is a continuation of my overview of the history of plants and their important influence on man.

The power of plants to survive.

The power of plants to survive originates with their unique beginnings a couple of billion years ago. The most primitive of plants, the slime molds, various classes of bacteria, algae, fungi, etc., were the substrates for the earliest bits of photosynthetic protoplasm. In colonizing the planet, some variety of plant life always succeeded, and, those that did not, yielded to breakdown to bacteria and fungi. From this process sprang new plant growth. Plant life that succeeds depends on plant life that fails. The rest of the natural world just helps everything else along.

Even lightning plays a pivotal role. It converts elemental nitrogen, the basis of all protein, into nitrates. These power, in the presence of sunshine, the miracle plants perform when accompanied by water, soil, air, and bacteria. Plants alone manufacture their own food. Plants create sugars, starches, and carbohydrates that will be consumed by some organism as food. It will eventually return to the soil or sea to complete and renew the cycle. Coincidental is the constant genetic mutation which guarantees survival in ever changing environs.

It takes eight seconds for sunlight to reach the earth's surface. In this sunlight plant chlorophyll converts carbon dioxide from the air and water from the soil into carbohydrates. Each year 150 billion tons of it are packaged for consumption. That's a lot of food, and it's for plant survival. That's why a 10,000 year old lupine seed from the arctic germinated in 1954. That's why primitive algae, lichens, mosses, and liverworts seem to live on absolutely nothing but air. Survival.

Plants have evolved a plethora of tactics to enhance survival through form, function, patterns of growth and movement. Some plants twine, form tendrils, hooks, thorns, rootlets. Some are parasitic, saprophytic, hydrophytic, epiphytic and so on. Some adapt to extremes of heat and cold using a wide variety of form modifications to reduce exposure and protect against water loss.

In an area where vegetation is frequently eaten by predators, some plants evolved to become poisonous. Such is the case with foxglove, horsetails, monkshood, daffodils and many others. Similarly, the vulnerable soon learn to avoid skin irritating plants like stinging nettles and poison ivy. The leaf spikes of holly, the thorns of roses, the needle like spines of many cacti tend to confer some protection from being consumed as food. Fewer predators is a step toward increased survival.

Sex in much of the plant world is the province of flowers. Their primary job is to reproduce the plant. Their main structures have specialized tasks that offer up fragrance, color, pollen and nectar. Anatomies vary enormously and parts are often so unique that only a single pollinator is effective. Many with heavy perfumes have little or no color and are often pollinated by night flyers, usually moths. No bright colors or patterns needed. Fragrance -- another tactic for survival.

As naturally follows, seed production and dispersal must guarantee success. The earliest and most important carrier is the wind. Many plants evolved to produce seeds with wings and streamers. A dandelion seed can travel a thousand miles in the air.

Other seeds that are heavier evolved different strategies. Impatiens species carry their seeds in pods that when dried out and mature explode propelling the seeds some distance from the parent plant. Some seed capsules are covered with little hooks, the burs of burdock, the inspiration for Velcro. Others may have very large hooks like Proboscida louisianica, nicknamed "dragon's claw" or "devil's claw". All of these seeds are carried far and wide by a variety of creatures, hitching rides on the feet and legs of animals, as well as boots, shoelaces and socks. Survival.

A mature oak tree can produce upwards of 90,000 acorns in a single season, and can live for hundreds of years. Animals eat, bury, and can transport these seeds great distances from their source.

A single tropical orchid provides in the neighborhood of 3.5 million seeds in a single flowering episode. One field mushroom releases 16 billion spores. A coconut tree produces between sixty and one hundred "nuts'. These seeds and spores can be carried great distances by rainwater flowing into brooks and streams and rivers. And, in the case of coconuts, 3000 miles on ocean currents. Water is another natural agent plants employ in order to survive.

Asexual or vegetative reproduction for some plants is an extremely easy survival technique. Stems and leaves of very many plants need only to fall on reasonably fertile soil to take root and grow. African violets, begonias and willows are examples, but don't forget the many weeds whose minuscule chopped up parts readily take hold and spread. Years ago, when I had my plant store, I sold leaves of a Kalanchoe nicknamed "good luck plant". This fleshy succulent forms plantlets along the toothed leaf margins. They fall to earth and form colonies wherever they touch the soil. As you know, strawberries (once strayberries) produce runners which are horizontal stems that extend out from the mother plant and set up home in a new location. The potato and other tuberous plants have a similar horizontal stem that is underground. Plant survival knows no limits.

The part of the plant that we witness daily is the gravity defying portion above ground. This seeming miracle is dependent on the unique relationship that roots develop with soil bacteria and fungi, hidden from sight. The thrust upward is "the force that through the green fuse drives the flower", is driven by the rich supply of water, nitrates, sugars and chemicals that the root hairs convert to nutrients and move to all plant parts. Roots are remarkable in their ability and strength. Roots of some plants can break through solid rock to obtain the moisture and minerals they require to supply the above ground component. A mature rye plant about five feet tall can have roots with a combined length of 380 miles. A sound and durable anchor to help in survival.

Water fills out plant cells and gives leaves and stems their firmness and resilience. Water is the transport system, the plumbing if you like, for the supply of nutrients. Any unused water is given off as vapor (transpiration). A single acre of corn can give off a quarter of a million gallons of water in a single season. Seventy-five percent of all rain that falls on land is the result of plant transpiration. One wonders if this isn't yet another survival tactic.

There are plants that grow where the substrate is so nutrient poor that they have evolved to nourish themselves by catching and digesting insect life to make up for the deficiency. It is their only chance for survival.

The list of limiting factors for a plant's chance of survival is long: pH, soil characteristics, available sunlight, temperature, nutrient competition, environmental severity. The harshest of circumstances such as lightning strikes and firestorms reveal the survival of our redwoods, the acacias of West Africa, the teak forests of India, and closest to home, the Pine Barrens of New Jersey. These recoveries and returns to vigorous health seem to us remarkable. We are the sentimental beings. This is the "force that through the green fuse drives the flower...", the force that allows the hollowed out apple tree across the way, 90% of its wood dead, only a thin ribbon of life remaining, to leaf out, flower, and fruit year after year. Survival.

to be continued... ( previous #2 of 7 ) ( next #4 of 7 )

From The Garden of Ed. Submitted for publication in The Towne Crier on May 18, 2005

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