[4] Endemic to central Ascension Island in the South Atlantic Ocean, P. purpurascens is known only from a single population on the upper slopes of Green Mountain at altitudes of 700–860 m (2,300–2,820 ft).

[citation needed] The fronds are large, measuring up to 1 m (3 ft 3 in) long, with purplish petioles and dark green, bipinnate leaves.

Its primary threats include habitat loss, invasive species, climate change, severe weather, and landslides.

The entire wild population is estimated to consist of 600–800 mature plants, and the small size of the area occupied by this species makes it especially susceptible to these threats.

Lower areas of this habitat have been partially smothered by Buddleja madagascariensis and Clerodendrum chinense, while other weeds such as Miconia crenata, Paspalum scrobiculatum, Piper aduncum, and Rubus species threaten to crowd out young ferns.