Irish Moss is a popular perennial groundcover, cherished for its dense, vibrant, moss-like texture and its use as a lawn substitute in small, specific areas. It is a good, low-growing choice for a landscape It consists of incredibly fine, thread-like, bright emerald-green leaves packed densely together to form a soft, cushiony carpet that closely resembles true moss. In late spring and early summer, the foliage is lightly sprinkled with tiny, star-shaped, white flowers. While they are very small, their sheer abundance can create a charming, airy effect.