An alva is a fruit that grows all over Bajor.
Alvas are used to make the beverage alva nut tea. (DS9 novel: Cathedral)
Dried alva was part of the staple diet of the Ornathia resistance cell during the Occupation as it warded off infection. (TLE - Terok Nor novel: Night of the Wolves)
In 2374, the Bareil Antos of the mirror universe ate alvas on Deep Space 9. Bareil greatly enjoyed the fruit, which he told Kira Nerys did not grow on the alternate universe Bajor. (DS9 episode: "Resurrection")
In 2376, Quark served alvas as part of reception for Federation, Bajoran, Trill and Alonis representatives on Deep Space 9. (DS9 novel: Twilight)