Rubus × 'Arapaho' is an early-ripening, erect, thornless blackberry cultivar released in 1993 by the University of Arkansas agricultural breeding program. Developed from a strategic cross made in 1982, its direct parentage consists of two thorny breeding lines designated as 'Ark. 631' and 'Ark. 883'. While both parents physically possessed thorns, they were selected because they were heterozygous carriers of the recessive genes for smooth-caned stems, a trait tracing back to the historic British cultivar 'Merton Thornless'. The cross successfully isolated this recessive thornless characteristic while incorporating the rigid, upright, and self-supporting structural architecture found in its thorny ancestry, which includes cultivars like 'Darrow', 'Hillquist', and 'Cherokee'.

The fruit of 'Arapaho' is distinguished by its short-conic shape, glossy black appearance, and exceptionally small seeds, which are significantly smaller than those of its contemporary relative, 'Navaho'. It holds a distinct position in cultivation for its early ripening window—often beginning harvest nearly two weeks ahead of other thornless varieties—and its ability to regenerate quickly by establishing thick fruiting rows via root suckers. The berries are characterized by a high concentration of anthocyanins and robust phenolic components, providing an intensely sweet flavor profile accompanied by excellent fruit firmness that prevents bleeding after harvest.