Oxossia annularis
Oxossia annularis is a shrub of Oxossia Turneroideae (Passifloraceae) native to eastern Brazil. It is found in Caatinga, Cerrado, and Atlantic Forest. O. annularis has 2–10 mm long petioles, rigid elliptical, ovate, or obovate leaves with serrated margins and heterostylous flowers. It was previously classified as Turnera annularis, however, recent phylogenetic analysis supports its classification as Oxossia. References 

Passifloraceae