Both broadleaf and narrow-leaf plantain have similar effects and can be ingested. The narrow-leaf one is easier to cultivate, so it is more frequently used in industrial production.
Plantain grows in places where there is human traffic and the soil is dense - perhaps the harsh conditions provide for the many valuable effects. Plantain leaves are the part of the plant worth collecting.
The harvested leaves are dried in a well-aerated and shady place away from direct sunlight.
The plantain contains glycosides with antimicrobial and soothing properties, which is the reason why application of fresh leaves to wounds is known to help.
An infusion good as cure for cough can be made from the collected and dried leaves (both broad and narrow). Take 1 tablespoon of dried plant per glass of boiling water. Leave to infuse for 1.5 hours, covered with a lid or wrapped in towel. Ingest one tablespoon 3-5 times a day. Symptoms of acute and chronic cough, bronchitis, asthma are all alleviated by the infusion.
The infusion helps stomach problems, such as gastritis, if the amount of acid in stomach is too low. However, if the amount of acid is increased, the infusion should not be used.
Disclaimer: Only use plants of which you are 100% certain. Do not consume plants that you don't recognize or plants that have grown in dubious locations. Consult your doctor about health issues and before beginning any course of medical treatment.