Rubus × 'Nessberry' is a historic interspecific hybrid developed in 1913 by the Norwegian-American botanist Helge Ness at the Texas Agricultural Experiment Station. It represents a foundational cross between the Southern dewberry (Rubus trivialis) and the domesticated red raspberry (Rubus idaeus 'Brilliant'). Initial generations of this cross yielded highly sterile, aneuploid offspring due to the differing ploidy levels of the parent species. To resolve this, Ness carried out selection through three generations of interbreeding until a spontaneous chromosome doubling occurred, stabilizing a fully fertile, tetraploid hybrid line. This breakthrough proved to breeders that highly divergent, wild trailing brambles and upright raspberries could be combined into fertile, stable cultivars.

The fruit of the 'Nessberry' combines the deep, rich coloration and aggregate drupelet adherence of its trailing dewberry parent with the distinct, aromatic flavor profiles inherited from the red raspberry. The plant maintains a sprawling, vigorous growth habit that requires a trellis, reflecting the trailing nature of Rubus trivialis, but features modified prickles that are far less formidable than those of wild dewberries. In gastronomic ethnobiology, the 'Nessberry' holds a monumental legacy as an ancestral germplasm; backcrosses of this cultivar later yielded foundational Southern varieties such as 'Regalness' and 'Flordagrand', making it a vital bridge in the history of warm-climate berry cultivation.