The calyx of a Convolvulus farinosus flower is cup-shaped with five acutely pointed tips, less than half the length of the corolla. Its colouring is rich, including green, yellow-cream and purplish brown. It is also hairy.
Convolvulus sepals are often not quite equal. There is a pair of tiny bracts on the peduncle of each flower (Pooley, 1998; Moriarty, 1997; Leistner, (Ed.), 2000; iNaturalist; http://tropical.theferns.info).