Aquilegia vulgaris is known for its spurred petals, giving the bloom its unique form and hence, one of its unique common names, Granny’s Nightcap. Better known as columbine, this European native is a perennial hardy to Zone 3, preferring meadows and woodlands, and doing quite well in dappled shade. A member of the ranunculus family, columbine is a poisonous plant, with one particularly interesting use. According to Plants for a Future, the seed of columbine can be dried and crushed, then used to kill parasites, such as head and body lice. Nice to know, just in case it comes to that.