Soleirolia soleirolii
A delicate, fast-spreading ground cover forming a dense, mossy mat of tiny bright green leaves, generally 1 to 4 inches tall and spreading indefinitely in suitable conditions. It prefers part to full shade and consistent moisture, growing best in cool, sheltered, well-drained spots and resenting hot, dry exposure. The foliage is the feature; flowers are insignificant. Use as a fine-textured filler in shaded beds, between stepping stones and pavers in cool gardens, around water features, and as a soft green carpet beneath ferns and other shade plantings.