The Tasmanian tree fern is one of the largest ferns in the world. Its trunk can grow to nearly 50 feet (15 m) tall, and the fronds or branches at the top can grow to 16 feet (5 m) long creating a canopy more than 30 feet (9 m) wide.
The Tasmanian tree fern is native to the tropical and subtropical forests of eastern Australia including the island of Tasmania. Tasmanian tree ferns, like most ferns, prefer moist, mild to very warm climates where frost and freezing weather never occur. Such conditions allow the Tasmanian tree fern to grow very old and tall. Some Tasmanian tree ferns live to be 500 years old. The Tasmanian tree fern grows very slowly. It grows about one to two inches (2.5-5 cm) a year.
Tasmanian tree ferns growing side-by-side create a nearly primitive landscape. Tree ferns once made up large forests on the Earth. Tree ferns have been found in the fossil record stretching back 200 million years to the Jurassic Period when dinosaurs roamed the Earth. Today Tasmanian tree ferns grow in many places around the world where winters are mild.
The Tasmanian tree fern commonly has a long straight trunk. A few tree ferns may have curved trunks. The “trunk’ is actually the decaying remains of earlier growth. This decaying matter accumulates and grows wider and wider as the tree ages. The fibrous trunks of dead organic matter can host epiphytic plants including other ferns and mosses. An epiphyte is a plant that grows on another plant but is not a parasite.
The Tasmanian tree fern is anchored in the ground by a rhizome. A rhizome is a creeping rootstalk that grows horizontally underground. When a portion of the rhizome grows vertically up through the soil it can form a new plant called an offset or plantlet. However, the Tasmanian tree fern reproduces mostly from spores rather than seeds. Spores grow on the undersides of some fronds. They look like tiny brown dots. The spores drop to the ground, germinate, and produce new plants.
The scientific name of the Tasmanian tree fern is Dicksonia antartica. Another tree fern that grows to the same size as the Tasmanian tree fern and is also native to the same part of the world is the Australian tree fern, Cyathea cooperi.