Cyathea acanthophora is a species of tree fern endemic to Kinabalu National Park in Borneo, where it grows in montane rain forest at an altitude of 1250-2000 m. The trunk is erect and can grow as tall as 5 m or higher. Fronds are 2-3 m in length and bi- or tripinnate. The stipe is dark towards the base and has slender spines. It is covered with scattered scales, which are glossy brown and have a narrow paler margin. Sori occur near the midvein of fertile pinnules. They are covered in thin, fragile indusia, which resemble small saucers.