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[Gene GeRue <genegerue AT ruralize.com>]

Even we avid gardeners take plants for granted. Until they succumb to  
disease because we put them in the wrong place or at the wrong time.  
We can't know too much about them. And never will.

Btw, should you ever have the opportunity to attend a talk by Peter  
Raven, take it. He is of vibrant energy, penultimately impassioned of  
plants, and profoundly informative. At an event I attended, questions  
from the audience included one to his attending mother: "Has he  
always been like this?" She answered in the affirmative, with a  
knowing smile.

Green, Life-Giving and Forever Young
By NATALIE ANGIER
Published: April 17, 2007

Show somebody a painting of a verdant, botanically explicit forest  
with three elk grazing in the middle and ask what the picture is  
about, and the average viewer will answer, “Three elk grazing.” Add a  
blue jay to the scene and the response becomes, “Three elk grazing  
under the watchful eye of a blue jay.”

What you’re unlikely to hear is anything akin to, “It’s a classic  
temperate mix of maple, birch and beech trees, and here’s a  
spectacular basswood and, whoa, an American elm that shows no sign of  
fungal infestation and, oh yeah, three elk and a blue jay.”

According to Peter H. Raven, director of the Missouri Botanical  
Garden, many of us suffer from an insidious condition called “plant  
blindness.” We barely notice plants, can rarely identify them and  
find them incomparably inert. Do you think that you will ever see a  
coma as vegetative as a tree? “Animals are much more vivid to the  
average person than plants are,” Dr. Raven said, “and some people  
aren’t even sure that plants are alive.”

But the antidote to plant apathy is at hand. As an unusually cool,  
sodden April edges toward May and spring’s cheeky blooms can be  
bridled no longer, botanists urge everyone to venture outside and  
check out the world through nature’s rose-colored glasses — and the  
daffodil, cherry blossom, dogwood and lupine ones, too. If this view  
doesn’t move you, you’re pushing up daisies.

As it happens, plants are not only alive in their own right. They are  
also the basis of virtually all life on earth, including ours. The  
core feature of planthood is autotrophy, that is, the happy ability  
to make one’s own food. Plants essentially eat the sun, transforming  
solar energy into sugars and starch through the stepwise enzymatic  
stitchery of photosynthesis. Animals, by contrast, are heterotrophs,  
defined by their need to devour other organisms — the hard-won fruit  
and fiber of the suneaters, or the once-removed flesh of herbivores.

Moreover, because plants release oxygen as a byproduct of  
photosynthesis, plants also give us aerobes leave to breathe. Our  
atmosphere is currently about 20 percent oxygen, all of it the bounty  
of the planet’s green-skinned autotrophs. “The most important  
chemical reaction on earth is photosynthesis,” said Robert DeFeo,  
chief horticulturist for the National Park Service. “We are all  
parasites upon it.”

Essential though plants may be to our survival, Dr. Raven emphasizes  
that they are a radically different form of organism than are  
animals. Plants and animals have evolved along separate paths for  
hundreds of millions of years, ever since single cells began pooling  
their talents into multicelled beings. “Plants have evolved their  
multicellularity completely separately from animals, and any direct  
comparisons between the groups are wrong,” Dr. Raven said. “It’s as  
if plants evolved on Mars, and animals here.”

In addition to their caloric self-sufficiency, plants can be envied  
for their eternal youthfulness. A plant elongates itself through  
constant cell growth in two zones of its body, at the very tips of  
the roots, which grow down into soil or other surface to which the  
plant clings, and the outer tips of the shoots, from which new  
leaves, flowers and fruits sprout. Whereas an animal, upon reaching  
maturity, has almost no young cells left in its body, Dr. Raven said,  
“in plants the ends of the roots and shoots are always juvenile,  
always growing, always babies.”

A plant is also always drinking, slurping water and nutrients the  
only way it can, through its roots. Everything needs water to  
survive, but another radical difference between the faunal and floral  
crafts is that while we can drink water and keep it circulating  
through the body via the bloodstream, water moves through a plant’s  
body in a continuous stream, entering through the roots, crawling up  
the stem and evaporating out through little openings, or stomata, in  
the leaves. In fact, the upward tug of evaporation is what pulls more  
water up from the soil, as the clingy water droplets follow each  
other skyward through the hollow capillaries of the plant’s stem and  
leaves, shinnying as high as 300 or 400 feet above ground in the case  
of the giant redwoods.

No, there’s no rest for the weary, especially if you’re immobile.  
Beyond feeding style, perhaps the biggest discrepancy between animals  
and plants is that animals can move, but plants are of necessity  
stuck in place. Unable to defend themselves by running away, plants  
have instead become crackerjack chemists, evolving a vast  
armamentarium of insect repellents, fungicides, microbicides,  
ultraviolet blockers and other defensive compounds that human  
chemists have just begun to tally.

Rootedness also complicates a plant’s love life, which brings us back  
to the blooming bounty of spring. Plants, like everybody else, want  
to spread their seed around and diversify their genetic stock through  
sexual reproduction, but it’s hard to meet fresh faces when you don’t  
have legs. A number of plant species like pine trees, oaks,  
cottonwoods and grasses rely on wind to blow their pollen around,  
with the hope that some of the male sperm contained therein will land  
on receptive female parts of their far-flung kind. Or if not the same  
kind, at least something in the same general group: the boundaries  
between plant species are far more porous than they are in animals,  
and different species and even genera of plants cross-hybridize with  
each other surprisingly often.

Nevertheless, wind sex is highly iffy and inefficient, and many  
species of modern plants, the angiosperms, instead manipulate members  
of the animal kingdom to serve as yentas in a more discriminating  
style. The plants offer up brilliant blossoms to entice a specific  
pollinating insect or bird, which gets drunk on the blossom’s nectar  
and wants more and so seeks out other blossoms of similar shape,  
color or scent. And as the bee or hummingbird flits from one favored  
flower to the next, it incidentally delivers pollen pockets to just  
the right spots. “We say, isn’t that beautiful, but the precise forms  
and shapes of flowers are adaptations to attract individual  
pollinators,” Dr. Raven said. When we eat, we are parasites on the  
foundational labor of plants; and when we “say it with flowers,” we  
are plagiarists, too.

http://www.nytimes.com/2007/04/17/science/17angi.html? 
em&ex=1177041600&en=6e33921fa94a9c15&ei=5087%0A