Norfolk Island Tree Fern (Cyathea brownii): Tallest Tree Fern with Smooth Trunk

Overview

Norfolk Island tree fern (Cyathea brownii), also called smooth tree fern, is endemic to Norfolk Island (between Australia and New Zealand). It is **among the tallest tree ferns in the world**, reaching 60–90 feet in its native cloud forests. Its massive trunk is distinctively **smooth and clean**, lacking the persistent leaf bases and scales of most tree ferns. The crown bears numerous arching, tripinnate fronds 15–20 feet long. A true giant of the tree fern world.

Record-Breaking Features

• Extreme Height: Potential 60–90 feet; one of the tallest ferns.
• Smooth Trunk: Clean, scarred surface unlike rough relatives.
• Cloud Forest Native: Adapted to cool, misty, high-humidity conditions.

Culture

Cool, moist, shaded conditions; deep, fertile, well-drained soil. High humidity; constant moisture. Frost tender; USDA zones 10–11. Requires vast space and ideal climate—botanical garden specimen.

Taxonomic Profile

A smooth-skinned titan of the fern world, Norfolk Island tree fern defines the upper limits of fern stature.