Alectoria imshaugii, commonly known as spiny witches hair, is a species of fruticose lichen in the family Parmeliaceae that occurs in North America. It was described as a new species by the lichenologists Irwin Brodo and David L. Hawksworth in their 1977 monograph on the genus Alectoria. The species epithet honors Henry Andrew Imshaug. The variety venezuelensis, proposed in 1994, occurs in Venezuela.