Stumpy Tree Fern

Botanical name: Dicksonia lanata subsp. lanata
Synonyms: Dicksonia laevis, Dicksonia lanata var. lanata
Common name(s): Stumpy Tree Fern, Tūākura, Tūōkura

About:
Dicksonia lanata subsp. lanata is one of New Zealand’s most unusual tree ferns. Unlike most members of the genus, it does not develop an upright trunk. Instead, it spreads by underground stems (rhizomes) to form extensive colonies of stiff, blue-green fronds. This distinctive habit allows it to create dense carpets across the forest floor, particularly in cool upland forests.

Natural habitat:
Occurs naturally in cool, moist lowland to montane forests, often beneath beech and podocarp forests where it forms large colonies across the forest floor.

Growing environment:
Prefers sheltered, cool, humid conditions with rich, well-drained, humus-filled soil. Thrives in full shade to filtered light and appreciates consistently moist conditions.

Endemic distribution:
Endemic to New Zealand. Found from the Coromandel Peninsula south through much of the North Island, although uncommon in the southern North Island, and throughout the northern and western South Island.

Height:
0.5–2 m (fronds)

Width:
Spreads indefinitely by creeping underground rhizomes, often forming extensive colonies.

Flowering:
Does not flower. Reproduces by spores.

Fruiting:
Produces spores on fertile fronds.

Uses:
• Native woodland gardens
• Forest restoration
• Understorey planting
• Natural groundcover
• Moist shaded banks
• Specialist fern collections

Appearance:
Growth habit:
A trunkless, colony-forming tree fern spreading by underground rhizomes rather than developing a single upright stem.

Fronds:
Stiff, slightly blue-green to green fronds up to 2 metres long arise from the ground on pale brown stalks. The stalks are covered with fine hairs that are visible under magnification.

Rhizomes:
Long creeping underground stems allow the plant to gradually spread and form large interconnected colonies.

Spores:
Sori develop along the margins of the fertile fronds, protected by the rolled-over edges of the leaflets.

Ecology:
Its dense colonies stabilise forest soils, retain moisture and provide shelter for native invertebrates, mosses and small forest plants. The spreading growth habit enables it to dominate the forest understorey in suitable habitats.

Associated habitats:
Podocarp forest, southern beech forest, montane forest, cool gullies, shaded slopes and moist upland woodland.

How to grow:
Plant in deep shade or filtered light in fertile, organic-rich soil that remains consistently moist but drains well. Protect from hot afternoon sun, drying winds and prolonged drought. Once established it requires little maintenance.

Propagation:
Usually propagated by division of established rhizomes or from fresh spores. Transplanting established plants can be difficult, so young divisions establish most successfully.

Cultural use:
Known traditionally by the Māori names tūākura and tūōkura. As a characteristic component of New Zealand’s cool native forests, it contributes to the distinctive appearance and ecology of many indigenous ecosystems.

Garden value:
An outstanding fern for cool, shaded native gardens where its unusual trunkless habit creates a lush woodland groundcover. Its ability to form broad colonies makes it ideal for naturalistic plantings and specialist fern collections, offering a distinctive alternative to upright tree ferns.