Asplenium adiantum-nigrum
black spleenwort
Europe, North Africa, and western and central Asia
Overview
Asplenium adiantum-nigrum is a small evergreen fern of the spleenwort family, forming tufts of fronds 10-40 cm (4-16 in) long from a short, scaly rhizome. Each frond has a glossy dark brown to black stalk in the lower part and a triangular, two- to three-times pinnate blade with firm, pointed, toothed segments. The leathery fronds are deep green above and persist through winter. Brown, linear sori develop along the veins on the undersides, releasing spores from summer into autumn. It grows in rock crevices, on old walls, scree, and shaded banks, usually on neutral to acidic substrates and tolerating both limestone and siliceous rock. The species withstands drought in its rooting crevices and deep shade but is slow to establish and resents disturbance once settled. Its dark stalks and stiff, triangular fronds give a compact, year-round structure in small spaces.
Native Range
Asplenium adiantum-nigrum is widespread across Europe, North Africa, and western and central Asia, with scattered occurrences in eastern Africa. It grows on rocky outcrops, walls, and shaded banks throughout much of its range. It ranges from coastal cliffs to mountain slopes.Suggested Uses
Asplenium adiantum-nigrum is grown in rock gardens, dry-stone walls, crevice gardens, and shaded containers where its evergreen fronds hold form year-round. It suits narrow crevices and vertical plantings that limit larger ferns. It is used to green shaded stonework and retaining walls.How to Identify
Appearance
Size & Dimensions
Height4" - 1'4"
Width/Spread6" - 1'
Bloom Information
As a fern it produces no flowers, reproducing instead by spores. Linear brown sori form along the frond veins from July to October. Ripe spores are released to the wind to establish new plants in damp crevices.
Detailed Descriptions
Foliage Description
deep green with black-brown stalksGrowing 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
Care & Maintenance
Care Guide
Grow in partial to deep shade on free-draining, gritty or rocky substrate, in wall crevices, rock gardens, or shaded raised beds. It tolerates neutral to acidic and limy conditions and brief drought once rooted, but standing wet and heavy, rich soil cause the crown to rot. The fern is hardy to frost across cool temperate zones and holds its fronds through winter. Deep, undisturbed planting in a crevice gives the steadiest results. It establishes slowly and dislikes being moved. Spores can be sown on damp, sterile compost to raise new plants.Pruning
Old or winter-damaged fronds can be cut away in early spring before new fronds unfurl. No other pruning is needed on this evergreen fern. Spent fronds are removed only to tidy the crown.Container Growing
✓ Suitable for container growing
Minimum container size: 1 gallons