Cyathea brownii - Norfolk tree fern

Cyathea brownii, also known as Sphaeropteris excelsa, is a majestic tree fern native to Norfolk Island. It is an impressive plant with a highly exotic appearance. With its slender "trunk" and delicately cut airy fronds, it creates a lush atmosphere reminiscent of tropical forests. Ideal for shaded gardens or spacious interiors, this fern is a popular choice among enthusiasts of exotic plants.

Cyathea brownii belongs to the Cyatheaceae family. This Cyathea genus, which includes around 470 different species, comprises the largest tree ferns in the world, with some species reaching heights of up to 30 metres. These plants are mainly found in the humid tropical and subtropical regions of the southern hemisphere. The Cyathea brownii is native to Norfolk Island, located in the southwest Pacific Ocean. In its natural habitat, it can reach an impressive height of over 20 metres, but when cultivated in our latitudes, the plant does not exceed 5 metres in height. In a pot, it will grow up to a maximum of 3-4 metres in height. This tree fern is characterised by a sturdy and slender stipe, topped with a crown of light green fronds (leaves), finely divided and measuring between 2 and 6 metres in length. Arranged in a crown at the top of the stipe, they give the plant a majestic and exotic look.

The fronds of Sphaeropteris excelsa are bipinnate to tripinnate. Each one is composed of a long, sturdy, dark brown to black petiole, covered with fine golden-brown to dark brown scales, characteristic of young developing fronds. The pinnae (primary segments) are long and arched, each bearing finely cut pinnules (secondary segments). These pinnules are lanceolate, deeply toothed, and have well-defined veins. They are generally light green to dark green, with a slightly leathery texture and a satin-like appearance. The young fronds unfurl in a spiral, a typical fern phenomenon called circinate vernation. During this phase, they are covered with protective reddish-brown scales.

In tree ferns, the stipe is the main "trunk" or stem that rises vertically above the ground. It is formed by the accumulation of the bases of old fronds (or leaves) after they fall. Unlike a true woody trunk, the stipe is made up of fibrous tissues and remains flexible yet resistant. It enables the fern to support its imposing foliage.

Tree ferns are not known for their great hardiness, except for the widespread Dicksonia antarctica. Cyathea brownii can only be grown in the ground in the most sheltered coastal gardens. In a colder climate, it will need to be planted in a container to be brought indoors in winter. In gardens where it can be grown in the ground, it serves as a centrepiece to create a tropical-inspired scene. It can be paired with giant foliage plants, such as Gunnera manicata, Brazilian Giant Rhubarb, by a pond, or with non-invasive bamboos like Fargesia papyrifera 'Blue Dragon'. To cover the ground, consider Farfugium, with its extremely decorative leaves.