Hi Debbie-lee,
Great question. Broad leaf plantain and long leaf platain have very similar application uses, but yes the long leaf is much more specific to toning the mucous membranes. You can work with broad leaf plantain at a similar dose and see how this goes. It’s a fairly safe plant, so you can try increasing the dose by about 25% over time if you think this person could use more.
Another lovely plant to support this situation could be mullein and/ or elderflower. However it does depend on the chronic condition and what may be causing this excess fluid to build. This is core to being able to help someone with plants.
Just a little note to keep in mind is that herbalists (community and practitioner level) should not be using the word ‘treat’ or ‘cure’. This is for liability reasons and mainly in relation to allopathic system and the overarching health body in Canada.
With warmth,
Benna