Thuidium delicatulum

Fern Moss, Delicate Fern Moss, Common Fern Moss

A carpet-forming moss from the temperate forests of North America, Europe, and Asia, where it spreads across forest floors, mossy rocks, and rotting logs in dense, pale-green mats. Each stem branches two or three times into fine, overlapping leaflets — a compound structure that gives the plant an uncanny resemblance to a miniature fern. It does best in 60–90% humidity with medium indirect light and consistently moist substrate, making it one of the most reliable ground-cover mosses for closed woodland terrariums. Given the right conditions it spreads steadily across soil, rock, or wood with minimal intervention.