Plagiothecium undulatum
waved silk-moss
Temperate Northern Hemisphere: Europe, northern Asia, and western North America
Container Friendly
Native to North America
SunFull Shade
WaterHigh
Overview
Plagiothecium undulatum is a robust, glossy, pale yellow-green to whitish-green moss that forms flat, spreading wefts and mats on the ground. Its main shoots are markedly flattened (complanate), 2-4 inches (5-10 cm) long, with the leaves spread into one plane so each shoot looks ribbon-like. The leaves are distinctly undulate, with regular transverse wrinkles that give the plant its common name and a satiny sheen. It grows on acidic soil, peat, leaf litter, and rotting wood, mainly in conifer and broadleaf woodland, on heaths, and on shaded moorland banks, favoring humid, shaded, lime-free sites. As a moss it has no roots, flowers, or true vascular tissue and takes up water directly over its surface, so it depends on constant humidity and declines if it dries out repeatedly. Reddish-brown spore capsules on slender stalks appear mainly in autumn and winter. It spreads slowly by growth and fragmentation to form extensive ground cover in suitable damp, shaded habitats. Its need for moisture and acidity limits where it can be grown.
Native Range
Plagiothecium undulatum is widespread across the temperate Northern Hemisphere, including much of Europe, northern and eastern Asia, and western North America. It grows in moist, shaded, acidic habitats such as conifer woodland, heaths, and moorland. It is most abundant in regions with cool, humid, oceanic climates.Suggested Uses
Grown as ground cover in shaded, acidic woodland and moss gardens and in damp, lime-free rockwork in cool, humid climates. It clothes banks, logs, and the ground beneath conifers and rhododendrons. Its need for shade, moisture, and acidity makes it unsuited to dry, sunny, or alkaline sites.How to Identify
Appearance
Size & Dimensions
Height2" - 4"
Width/Spread1' - 2'
Bloom Information
This moss reproduces by spores rather than flowers. Reddish-brown spore capsules are carried on slender stalks (setae) and ripen mainly in autumn and winter. The capsules are inclined and curved, releasing spores that disperse on air currents.
Detailed Descriptions
Foliage Description
Glossy pale yellow-green to whitish-greenGrowing Conditions
Sun Requirements
Tolerates up to 2 hours of direct sunlight daily
• Full Sun: 6+ hours of direct sunlight
• Partial Shade: 3-6 hours of direct sunlight
• Full Shade: Less than 3 hours of direct sunlight
Water & Climate
Water Needs
Care & Maintenance
Care Guide
Plagiothecium undulatum grows in shade to deep shade on moist, acidic substrates such as peat, leaf litter, humus, and decaying wood. It needs consistently high humidity and lime-free conditions and does not tolerate drought, full sun, or alkaline soil. It is not grown from seed; established mats or fragments are laid onto suitable damp surfaces and kept moist while they knit together. No feeding is required, and fertilizer or disturbance tends to harm it. It withstands cold well but fails where the surface dries out repeatedly. It suits shaded woodland gardens and moss gardens in cool, humid climates.Pruning
No pruning is required. Mats can be lifted, divided, or pressed back into place by hand, and unwanted growth scraped from surfaces where it is not wanted.Container Growing
✓ Suitable for container growing
Minimum container size: 1 gallons