Explain the structure of a pitcher.

Explanation

1. The leaf becomes modified into a pitcher in Nepenthes and Sarracenia.
2. In Nepenthes the basal part of the leaf is laminar and the midrib continues as a coiled tendrillar structure.
3. The apical part of the leaf as modified into a pitcher the mouth of the pitcher is closed by a lid which is the modification of leaf apex.