The Fascinating World of Plants
Plants are classified on the basis of similarity of structure and function: the greater the similarity, the closer the relationship.
Monocotyledons refer to plants whose seeds contain one seed leaf. (Fig. 7:1) Dicotyledons refer to plants whose seeds contain two seed leaves. (Fig. 7:2)
     Figure 7:1 - Monocotyledons (Monocots)
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Figure 7:2 - Dicotyledons (Dicots)	 
	

A CLASSIFICATION OF THE MAJOR PLANT GROUPS
with illustrative listings of representative plants in Group VI
Spore Plants                        Seed Plants
Group I           Group IV                    Group VI
                                              Flowering plants
Bacteria          Cycads
Algae             Pines and
Fungi             other conifers      Monocotyledons      Dicotyledons
Lichens           Firs                Corn                Beans
Mushrooms         Cedars              Palms               Rubber
                                      Canes               Cocoa
Group II          Group V             Pandanus            Coffee
Mosses            Parasitic plants    Orchids             Oranges
                  Dodder              Lilies              Breadfruit
Group III         Mistletoe           Bananas             Casuarina
Ferns                                 Taros               Yams
                                      Sedges              Croton
                                      Grasses             Crotolaria
                                      Onions              Most garden                                                                   flowers,
                                      Vanilla             vegetables, etc.
Note the following details concerning some of the above plants:
GROUP I
BACTERIA (Fig. 7:3)
These are very tiny microbes that cannot be seen without a microscope. Some have spores and some do not, but they all belong to one group called bacteria. Some bacteria are good and help other living things, including people. Some are very destructive and harmful, causing serious diseases in both plants and animals and much financial loss.
    
Figure 7:3 - Bacteria species showing three basic cell shapes.
    	  
	 
	

Figure 7:4 - Marine algae.
 
 



ALGAE (Fig. 7:4)
These are the seaweeds and the water weeds that grow in rivers and ponds and in the upper layers of the soil. Some are good for man to eat; and some fish live on others. Some are used for making jellies.
FUNGI (Fig. 7:5)
There are many kinds of fungi that are classified into many orders and families. The commonest molds like the blue and black ones are seen inside rotten oranges or on their dirty furry skin and on old pieces of bread or bad copra. Others grow into the large bracket fungi that are found on old posts or logs.
Mushrooms are another type of fungi. Some mushrooms can be eaten, whereas toadstools and some mushrooms are poisonous and must not be eaten. Some fungi, too small to see without a magnifying glass, grow on the leaves of plants or within them and cause disease.
Several common fungus diseases are important to the gardener: Rhizoctonia, or damping-off of seedlings and older plants; Pythium and Phytophthora, which destroy roots of many vegetable plants and trees; Alternaria, late blight of tomato; and Anthracnose, which is very destructive to beans as well as to other plants. These will be discussed in later chapters.
 

     
		RHIZOPUS (BLACK BREAD MOLD)
Figure 7:5 - Several fungi.
 
 



LICHENS (Fig. 7:6)
These are the hairy-looking pale green or gray things that grow on or hang down from some branches of trees in damp climates. Some look like old men's beards and are called beard lichens. Others only form a black-, gray-, blue-, or orange-colored skin on tree branches or rocks. Lichens do not cause disease.
 Figure 7:6 - Lichens.

GROUP II
MOSSES (Fig. 7:7)
Mosses are the soft, dark green, furry little plants that grow on wood and rocks or on the soil in the damp, shady places that they prefer. On high mountains not many plants other than mosses will grow. Some mosses are used for packing young plants for shipment to keep them moist; others, such as peat and sphagnum mosses, are used to good advantage in special soil mixtures. Mosses are propagated by spores.
      
 

Figure 7:7 - Mosses.

GROUP III
FERNS (Fig. 7:8)
Ferns comprise a large family; some are as large as trees and some are small. They are multiplied by spores, a brown powder produced on the leaflets. They are not very useful, with the exception of some that are eaten in tropical areas and certain climbing ferns used in making rope and baskets. Ferns play an important part in beautifying a yard or landscape.
   
 

Figure 7:8 - Ferns.   
GROUP IV
CYCADS (Fig. 7:9)

These are mostly small trees that look something like tree ferns or palms. Some grow to a large size. Other varieties have leaves that are said to be poisonous to cows and horses.
PINE TREES (Fig. 7:10)

There are many varieties of pine. They grow in many places around the world and are used primarily for erosion control, lumber, and plywood.
GROUP V
FLOWERING PLANTS (Fig. 7:11)
These are of two kinds, monocotyledons and dicotyledons, which are commonly called monocots and dicots. Mono means one, and di means two. Cotyledon means seed leaf. It refers to the leaf, or leaves, that the seedling has when it starts to grow. It is already present in the seed, although sometimes not readily distinguishable. Corn is an example of a monocot; beans, of a dicot.
The family relationships in the botanical classification are of greatest importance insofar as vegetable growing is concerned. The seeds of the vegetables within a family may be somewhat similar in size and shape. This fact helps one know the proper depth of planting and the type of seedbed preparation needed. Usually the members of a family are susceptible to attack by the same insect or diseases, so the grower can be on guard. The foliage of the members of the parsley  family, for example, is tolerant of oil. Knowing the members of this family enables one to know the type of plant on which an oil spray may be used to kill weeds.
Botanical books differ slightly in their terminology. The following classification includes the more important vegetables.
   

 Figure 7:11 - Some monocot and dicot plants.