A new and distinct plum tree variety, Prunus salicina, cv. ‘Suplumfifty’ is characterized by fruit having deep red flesh, nearly black skin, and a cling stone. The fruit is medium in sugar and has low acidity. The fruit of the new variety ‘Suplumfifty’ is also moderate in juice and has a sweet-mild flavor. The date of the harvest of the fruit of the new variety is later than for ‘Black Splendor’ (unpatented). The fruit of the new variety ‘Suplumfifty’ ripens with nearly same timing as the fruit of ‘Black Kat’ (U.S. Plant Pat. No. 13,134) but with a deep red flesh compared to amber-colored for ‘Black Kat’.
