Pteris tremula is a terrestrial fern, with its fronds arising from the ground up to 1.3 m (4.3 ft), rarely up to 2 m (6.6 ft) tall. The stipe is brown. The light green lacy compound fronds may reach 2 m (6.6 ft) in length and are 3-pinnate or more. The brownish sori line the undersides of the frond margins. Unlike Pteris vittata and other Pteris species, it is not able to hyperaccumulate arsenic and is damaged by levels as low as 25 mg/kg in the soil. The plant contains two cytotoxic indanonic sesquiterpenes.