Definite identification of the plant & harvesting of the correct plant family

The pharmacognosist must collect the samples of the plant if possible with flowers and fruits in order to identify it with certainty.
Correct botanical identification of the plant is essential for the purpose of carrying a thorough bibliographic study and also to prevent unnecessary duplication of work.
After the definite identification of the plant has been established, sufficient amount of the plant material must be collected so that entire research project may be performed. However gathering must be done carefully so that no extraneous plants are mixed and materials collected are free from any disease.