Alsophila cunninghamii, synonym Cyathea cunninghamii,[1] also known as the gully tree fern and slender tree fern, is a species of tree fern indigenous to New Zealand[2] including North Island (type locality), South Island and Chatham Islands; also to Victoria, possibly New South Wales, southeastern Queensland and Tasmania in Australia.

[3]: 36  It grows in damp forest, often emerging from stream gullies and riverbanks.

Brownsey[2]: 103  noted that it has a lower tolerance for drought than other related species.

Sori occur along each side of the pinnule midvein and are covered by hood-like indusia.

The specific epithet cunninghamii commemorates Allan Cunningham (1791-1839), a botanist who traveled widely in Australia and New Zealand.