A Kaferian apple is a type of fruit native to the planet Tau Ceti III. By the 23rd century, Kaferian apples were considered quite a delicacy, and were known for their great taste. (ST reference: The Worlds of the Federation)
Humans had known of Kaferian apples as early as 2151, as it was on the cover of a noted interplanetary guidebook. (ENT episode: "Strange New World")
When Lieutenant Commander Gary Mitchell became mutated into a superbeing in 2265, he had the ability to create a Kaferian apple tree on Delta Vega. (TOS episode: "Where No Man Has Gone Before")
In 2376, Treir served Morn a breakfast plate of Skorrian fritters in a Kaferian apple compote. (DS9 - Mission Gamma novel: Twilight)
In the late 26th century, Rojan grew a large number of Kaferian apple trees in his orchard on the Kelvan colony. (TOS - Strange New Worlds 9 short story: "Gone Native")
In 2258 of the alternate reality created by Nero's incursion to the year 2233, the mutated Gary Mitchell created a Kaferian apple before offering it to James T. Kirk. (TOS comic: "IDW Star Trek, Issue 2")
Another variety of Kaferian apples.