Hawthorn, also called mayflower, thornapple, whitethorn, or hawberry , is a dense, thorny shrub of the rose family native to northern climates. Hawthorn berry is a rich source of polyphenols, which are antioxidant compounds found in plants. Hawthorn may have anti-inflammatory properties. Traditional Chinese Medicine commonly suggests hawthorn for blood pressure. Studies suggest that hawthorn may support cardiovascular function and help maintain normal, healthy blood pressure levels.