P. hillardiae is a perennial shrub or groundcover that is more often grown as an annual and self seed readily. The green shrub is covered with intense blue flowers during Autumn. A shade-loving option for dry spaces in the garden. P. hillardiae have two subspecies: P. hillardiae subsp. hillardiae and P. hillardiae subsp. australe, both found naturally in river stream banks in Pondoland.