
14 A TEXTBOOK OF GENERAL BOTANY 
Another class of plants, instead of manufacturing their 
food, absorb it from decaying organic matter. These are sap- 

Fig. 9. Monotropa 
(Indian pipe), a sap- 
rophyte with color- 
less leaves. (x 3) 
rophytes. Numerous saprophytic flowering 
plants obtain their food from decompos- 
ing organic matter in the soil (Fig. 9). 
These, like the parasites, lack chlorophyll 
and are frequently colorless; they may 
have various colors, but they never have 
the green color of chlorophyll. The most 
numerous of the parasites and saprophytes 
belong to the lower groups of plants. Most 
of the bacteria and all of the fungi either 
are parasitic on plants or animals or are 
saprophytic. 
Annuals, biennials, and perennials. Ac- 
cording to the length of time they live, 
plants are designated as annuals, biennials, 
and perennials. Those that live for only 
one year or a single season are annuals; 
these include our cereals, such as corn, 
rice, and wheat, and many of our vege- 
tables, such as tomatoes, cucumbers, etc. 
Plants such as beets and carrots that do 
not produce seed until the second summer 
or fall after they are planted are diennials. Plants like the 
dahlia and sweet potato that live from year to year, or through 
a series of years, are perennials. 
a a 
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