P. americana may refer to:
Paradelphomyia americana, a crane fly species in the genus Paradelphomyia Periplaneta americana, the American cockroach, palmetto bug or waterbug Persea americana, the avocado, aguacate, palta, butter pear or alligator pear tree Pilularia americana, the American pillwort, an aquatic fern species Prunus americana, a species of plum tree Phytolacca americana
See also Americana (disambiguation)