CHAPTER XIII 



CLASSIFICATION OF PLANTS ACCORDING TO THEIR 

 MODE OF NUTRITION 



1. Green plants. 



2. Non-green plants 



(a) Saprophytes, 

 (6) Parasites. 



3. Insectivorous plants. 



4. Symbiotic plants. 



1. Green Plants. These plants are autotrophic, or self- 

 nourishing. They are able, by means of the chlorophyll 

 present in their green cells, to form, during sunlight, carbo- 

 hydrate from carbonic acid gas. The nitrogen required 

 for the synthesis of proteins is obtained, not from the air, 

 but from mineral salts present in the soil. 



2. Non-Green Plants. These, not possessing chloro- 

 phyll, are unable to make carbohydrate for themselves. 

 They must therefore obtain it from sources outside their 

 own bodies i.e., they are hetero trophic. Not needing 

 light for photosynthesis, they generally live in darkness. 

 According to the nature of the source from which they 

 obtain their food, non-green plants are divided into two 

 groups Saprophytes and Parasites. 



(a) Saprophytes (Gr. sapros, rotten). These are colour- 

 less that is, non-green plants which obtain their carbo- 

 hydrate from the rotting products of vegetable or animal 

 remains. Animal excrement, since it contains organic 

 material exposed to decay, is a minor source. The 

 majority of fungi are saprophytes ; not being able to make 

 sugar for themselves, they get it from the humus in 

 which they grow. Soil-bacteria are saprophytes, and so 

 are all those bacteria which initiate putrefaction or bring 



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