This is similar to brevisepalus but has longer sepals (ca. 4-8 mm at anthesis versus 2-4 mm), distinctive reddish-purple flowers on strongly acending peducles, and narrower leaves (ca. 0.5-2 cm versus 1.5-3.5 cm). It mostly occurs on sandy soils of the southeastern Coastal Plain from Ala. to Va. Colls. from Ky. have been reported in SERNEC (2020) and in other herbarium databases from CLAY (EKY), EDMO (NY) and ROCK (NCU), but these records appear to be based on misidentifications. P. australis has also been reported from w. and c. Tenn., including Stewart Co. adjacent to Ky. (APSC; Ch), but all records from Tenn. are incorrect according to D. Estes (pers. comm. and Ch+).