The reason that it got the name ‘Oyster Plant’ is because during pollination, the bees have to force themselves between the top and bottom lips of the flower petals, rather like a chef forces open oysters.
The alternative nickname ‘Bear’s Breeches’ possibly arose from the simple fact that some styles of dress breeches that were worn years ago were tight fitting, especially those that were used for livery, formal and court dress. A major use of Acanthus mollis is for treating any dislocated joints; first it assists by relaxing the joint and then tightening it to help reposition the dislocated articular surfaces as they should be. This tightening can be seen as being synonymous to being confined in tight clothing.
The whole plant, from roots to flowers, secretes a viscous liquid emollient, which is both astringent and also a very effective detergent. It is known to contain abundant mucilage, tannins, carbohydrates, minerals and has a bitter quality. It has been used during treatment to soften tissues and tumours. Its properties as an astringent, antidiarrhoeal, expectorant, make it useful in cases of bronchitis, colds, diarrhoea, liver problems. Externally, it can be used as a poultice to repair damaged joints, healing wounds and burns, assisting scar tissue, stomatitis of the mouth and lips, pharyngitis and vaginitis. The American Indians applied the leaves to venomous snake bites.