Kalmia angustifolia is accepted species in  the family Ericaceae  subfamily: Ericoideae, tribe: Phyllodoceae,  
Genus Kalmia 
This species is found in Connecticut, Delaware, Georgia, Labrador, Maine, Maryland, Massachusetts, Michigan, New Brunswick, New Hampshire, New Jersey, New York, Newfoundland, North Carolina, Nova Scotia, Ontario, Pennsylvania, Prince Edward I., Québec, Rhode I., South Carolina, Tennessee, Vermont, Virginia, West Virginia.