The slender stems measure up to 10 cm (3.9 in) in diameter and have prominent leaf scars encircling the trunk.

[2][6][7] The crown consists of between 3 and 13 paripinnate fronds to 3 m (9.8 ft) in length, with 15-40 pinnae (leaflets) on either side of the rachis (midrib), and have a crownshaft which measures about 70 cm (28 in) long.

[6][7] The leaflets measure up to 56 cm (22 in) in length, are regularly or irregularly arranged (often clustered), with nearly parallel margins and a truncated tip.

[2][6][7] There is a thin layer of flesh around the solitary seed, which is about 12 mm (0.47 in) long with five deep longitudinal grooves.

[6] The genus name Ptychosperma is derived from the Ancient Greek word ptukhḗ, meaning "a fold"; and spérma, "seed".

[3][7][11] P. macarthurii is classified as endangered in the Northern Territory where its distribution is limited,[7] but in Queensland it is listed as least concern.