See quotations. The meaning is obscure.
1837. Forbidden fruit, citrons, lemons and limes are rapidly increasing.—John L. Williams, ‘The Territory of Florida,’ p. 113 (N.Y.).
1848. Papa invites no one to the house but forbidden clerks, Quakers, and gray heads.—W. E. Burton, ‘Waggeries,’ p. 28 (Phila.).
*** Forbidden fruit is especially the Citrus Paradisi.
