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Callicladium spp.
callicladium moss
Northern hemisphere temperate and boreal forests
Overview
Callicladium is a genus of pleurocarpous mosses in the family Hypnaceae, growing as flat, spreading mats rather than as upright plants. The commonly recorded species, C. haldanianum, forms glossy yellow-green to golden patches 0.4-1.2 inches (1-3 cm) deep over rotting logs, tree bases, stumps, and humus-rich soil. Slender, irregularly branched stems creep horizontally and carry small, concave, lance-shaped leaves about 0.08 inch (2 mm) long that curve to one side when dry. Like all mosses, the genus has no roots, flowers, or vascular tissue; it takes up water directly over its surface and anchors by thread-like rhizoids. Reproduction is by spores released from cylindrical capsules raised on reddish stalks 0.4-0.8 inch (10-20 mm) tall in late autumn and winter. Callicladium occurs across cool, moist temperate and boreal forest in the northern hemisphere and depends on steady humidity and shade, drying to a duller, contracted mat when conditions turn hot and exposed.
Native Range
Callicladium is distributed through cool temperate and boreal regions of the northern hemisphere, including North America, Europe, and northern Asia. It grows in moist, shaded forest on decaying wood, stumps, log surfaces, tree bases, and peaty or humus-rich soil.Suggested Uses
Callicladium is used in moss gardens, terrariums, and shaded naturalistic plantings on logs, stumps, and damp ground. It can green over rotting wood and bare humus in cool, shaded settings. Its need for constant moisture and shade rules out open, sunny, or dry sites.How to Identify
Appearance
Bloom Information
Mosses do not flower. Spore capsules mature mainly in late autumn and winter, releasing spores as the capsule dries and its mouth opens. The genus also spreads vegetatively when detached stem fragments take hold and form new mats.
Detailed Descriptions
Foliage Description
Yellow-green to goldenGrowing 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
Care & Maintenance
Care Guide
Callicladium is rarely cultivated and is met mainly in woodland on rotting wood, or in moss gardens and terrariums. It needs constant shade, high humidity, and a damp organic surface such as decaying wood or peaty soil, and it browns and contracts in direct sun or dry air. It takes no fertiliser and draws moisture and minerals from rain and surface films rather than from roots. Established mats can be lifted and pressed onto new damp wood or soil to spread them. Slugs and drought are the main causes of patchy loss.Pruning
No pruning is needed. Mats can be trimmed or torn to shape, and the removed pieces laid on fresh damp substrate to start new growth. Accumulated leaf litter can be lifted off so the mat is not smothered.Container Growing
Suitable for container growing
Minimum container size: 1 gallons