All species are shrubs, though some can grow quite large; for example P. tomentosus may become, at up to high, a small tree. Like the closely related serrurias they have divided leaves, though a distinctive feature of the genus is that individual plants of some species can bear both normal leaves and ones that are only minimally or even undivided. Other strange features of the leaves are that they do not have distinct upper and lower surfaces and their venation is primitive. The flowerheads are spike-like inflorescences in which the flowers are grouped into fours, with each group of four carried beneath a leathery bract. The shell-like bracts remain on the plant for a year or longer, well after the seeds have dropped off. The plants are not serotinous. They do not resprout after fires but regenerate from seeds which are shed soon after flowering.
