E.
Furthermore, standard and dwarf Ruby Red Grapefruit Trees bear large-sized grapefruit that have red-blushed yellow rind and sweet, luscious deep ruby flesh. But the discovery of the mutated red-fleshed, sweet-flavored Ruby Red grapefruit tree changed all that, and gave birth to the great Texas grapefruit industry.It is a bud sport (mutation of one tree limb that bears fruits that have different characteristics than the rest of the tree) that grew on the limb of a Pink Marsh grapefruit tree.