Atrichum undulatum
Catherine's moss
Temperate Northern Hemisphere - Europe, Asia, and North America
SunPart Shade – Full Shade
WaterMedium
Overview
Atrichum undulatum is a medium-sized acrocarpous moss forming loose, dull-green patches or scattered shoots on bare soil. The lance-shaped leaves are 5-9 mm (0.2-0.35 in) long, strongly undulate with wavy transverse ripples when moist, and edged with toothed margins and low ridges of cells along the midrib. When dry the leaves curl and twist, dulling to a darker green. Male and female organs occur on separate shoots; fertilised plants raise a slender, curved, cylindrical spore capsule on a red-brown stalk 2-4 cm (0.8-1.6 in) tall. It colonises disturbed, shaded ground such as woodland banks, path edges, ditch sides, and clay soil in gardens. The moss favours moist, neutral to acidic, loamy or clay soils and shade, and it dries out and shrinks on exposed or droughty sites. Its low, undulate shoots give a soft green film over bare earth rather than a deep cushion.
Native Range
Atrichum undulatum is widespread across the temperate Northern Hemisphere, including Europe, much of Asia, and North America. It grows on bare, disturbed soil in woodland and shaded banks throughout this range. It ranges from lowlands into hill country.Suggested Uses
Atrichum undulatum is used in moss gardens, shaded woodland plantings, terrariums, and on bare soil banks where it forms a low green cover. It suits damp, shaded sites and disturbed clay soils that bare easily. It is grown for ground-level texture rather than height or flower.How to Identify
Appearance
Bloom Information
As a moss it produces no flowers and reproduces by spores. Curved, cylindrical capsules rise on reddish stalks 2-4 cm (0.8-1.6 in) tall, mostly maturing from autumn through spring. Ripe capsules shed spores from a toothed mouth in damp weather.
Detailed Descriptions
Foliage Description
dull greenGrowing Conditions
Sun Requirements
Tolerates up to 4 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
It grows in partial to deep shade on moist, neutral to acidic, loamy or clay soil, on banks, path edges, and bare ground in woodland gardens. As a moss it has no true roots and takes water and nutrients over its whole surface, so steady humidity and shade matter more than soil fertility. It tolerates winter cold but shrivels in drought and strong sun, reviving when moisture returns. Compacted, shaded soil with little competition from larger plants favours it. It spreads by spores and by fragments rather than by sowing. Disturbed, weed-free soil lets it colonise.Pruning
As a low, ground-hugging moss it is not pruned. Fallen leaves and competing weeds are cleared from the surface to keep patches open. No cutting is needed.Container Growing
✓ Suitable for container growing
Minimum container size: 1 gallons