Ray florets have

Epigyne: In an epigynous flower, the margin of the thalamus grows and completely encloses the ovary. The calyx, corolla, and Androecium arise above the ovary.  The ovary, in this case, is described as inferior. E.g. Sunflower, Cucumber. 

In sunflower or Helianthus or sunflower, the peripheral or outer, zygomorphic flowers are called ray florets; whereas central or inner, actinomorphic flowers are known as disc florets.