The American Society of Plant Biologists twelve Principles of Plant
Biology are very worthwhile but I think twelve is too few. Here's a
draft of what I would add for a second twelve. Any other suggestions?
13. Plants are the dominant land organisms on a mass basis. "The mass
of vegetation on the Earth very far exceeds that of animal organisms;
for what is the volume of all the large living Ceteacea and Pachydermata
when compared with the thickly-crowded colossal trunks of trees, of from
eight to twelve feet in diameter, which fill the vast forests covering
the tropical region of South America ?"
Alexander von Humboldt 1858
14. Plants often clone themselves, both vegetatively and by
self-pollination followed by self-fertilization to produce seeds. For
example, the pea cultivars Gregor Mendel started with were basically
15. Plants adapt to diverse environments partly because they have
tremendous phenotypic plasticity. For example, an old tree on nutrient
poor soil or in a harsh environment may be 5% or less the height of a
tree of the same species and age in a better environment.
16. Plants have tremendous diversity in habit (trees, shrubs, herbs,
bulbs, vines, epiphytes, aquatics, succulents, etc.).
17. Some plants have incredible longevity. For example, bristlecone
pines can approach 5,000 years old, a King's holly shrub is about 43,000
years old and the 'Pando' quaking aspen clone may be over a million
18. Not all plants are photosynthetic. Over 300 species are parasitic
and therefore heterotrophic, including important weeds such as dodder
and broomrape, and the world's largest flower Rafflesia.
19. Plants have coevolved with many organisms, including mycorrhizal
fungi, nitrogen-fixing bacteria, ant protectors, animal pollinators
animal seed dispersers and most recently humans.
20. Plants have many important roles in society including as symbols,
memorials, toys, gifts, decorations, tourist attractions, state trees,
state flowers and in art, architecture, humor, literature, poetry and
religion. Plants also often appear on coins, currency, stamps and flags.
21. Plants have played an important role in human history such as the
economic collapse in early 1600's Holland due to speculation in tulip
bulbs and Columbus's search for spices that resulted in the discovery of
22. People have severely damaged natural plant populations by
introducing thousands of foreign plants, animals and microbes that have
decimated native plant populations. For example, the American chestnut
was virtually wiped out by an introduced fungus.
23. Without plants, our outdoor environments would be barren and harsh.
Landscape plants enhance our environmental quality by providing shade
and beauty, moderating temperatures, screening unsightly views,
preventing erosion and reducing windspeed.
24. Plants have long been neglected and discriminated against in biology
teaching, which has caused an epidemic of plant illiteracy and numerous
widespread plant misconceptions.
David R. Hershey
dh321 at excite.com
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