Irish Moss (Sagina subulata) is a low-maintenance ground cover that is perfect for use in rock gardens, between pavers, at the edges of a path, and as a low-footfall, limited area lawn substitute.This lush and low-growing evergreen perennial resembles moss, but it's actually part of the Carnation family (Caryophyllaceae) and has much different growing requirements.Sometimes referred to as Pearlwort, it's often confused with a similar, but less common species called Scotch Moss (Arenaria verna). While alike, Irish Moss stays a vibrant green throughout the year and Scotch Moss has a more golden shade.When in bloom, both types have little white flowers. The Irish Moss variety are solitary, whereas those found on Scotch Moss appear in clusters.