Crab Apple
The fruit is astringent and laxative. The crushed fruit pulp can be used as a poultice to heal inflammations or small flesh wounds. The fruit is eaten to obviate constipation. The bark, and especially the root bark, is anthelmintic, refrigerant and soporific. An infusion is used in the treatment of intermittent, remittent and bilious fevers. The leaves contain up to 2.4% of an antibacterial substance called "florin". This inhibits the growth of a number of gram-positive and gram-negative bacteria in as low a concentration as 30 ppm.