A Closer Look at Plant Classifications, Parts, and Uses
CHAPTER 1 CHARACTERISTICs oF PLANTS W herever there is sunlight air and soil plants can be found On the northernmost coast of Greenland the Arctic poppy peeps out from beneath the ice Mosses and tussock grasses grow in Antarctica Flowers of vivid color and great variety force their way up through The Arctic poppy can bloom even under barren conditions Shutterstock com Io
CHARACTERISTICS OF PLANTS the snow on mountainsides Many shrubs and cacti thrive in deserts that go without rain for years at a time and rivers lakes and swamps are filled with water plants The scientists who study plants botanists have named and described approximately 270 000 different kinds of plants They estimate that another 30 000 unidentified species exist in less explored ecosystems such as tropical forests PLANTS AND THE BALANCE OF NATURE Plants are essential parts of ecosystems Most of the energy consumed in terrestrial ecosystems is provided by plants and as a consequence land animals are dependent on them for their food Plants absorb minerals such as potassium and phosphorus from the soil These are stored in plant tissues and are an essential part of the diet of animals that eat plants Plants help form enrich and sta bilize soil Hearty mosses help break down and crumble rock into soil The roots of trees and other plants also contribute to this process Decaying plant material such as leaves increases the fertility of soil Plant roots hold the soil in place and prevent erosion II
A CLOSER LoOK AT PLANT CLASSIFICATIONS PARTS AND Us I2
CHARACTERISTICS OF PLANTS WHAT DISTINGUISHES PLANTS FROM OTHER LIVING THINGS Exactly what is a plant and how is it differ ent from other life forms Initially this may seem like a simple question Everyone knows that an elm tree is a plant whereas a dog is not Nevertheless the precise definition of plants is still a matter of debate among some scientists As recently as the late 1960s scientists believed that all organisms could be classified as members of either the plant or the animal kingdom Life forms that are green and that can synthesize their own food using light energy were put in the plant kingdom Those organisms that lack green pigment and are able to move about were considered to be animals As scientists made more detailed studies of certain organisms that were con sidered to be plants they recognized that they were quite different from plants and that they did not share an evolutionary his tory with them Herbivores like horses get many minerals from plants Hemera Thinkstock 13
