2d. Section Rubus

Canes stout with considerable branching, sometimes persisting more than two years. Stipules lateral. Perhaps as many as 300 species, native to the Old World, primarily in western and central Europe.

Treatments vary widely in the number of species recognized. Steyermark (1963) accepted three naturalized taxa in sect. Rubus: R. bifrons Vest, R. laciniatus, and R. procerus. Rubus laciniatus is a distinctive taxon that is clearly defined. Rubus procerus was the name that Steyermark applied to the Himalayan blackberry, an invasive species whose correct name is a matter of some controversy. The present treatment follows those of Evans and Weber (2003) and Zieliński (2004) in using the name R. armeniacus. No specimens confirming the presence of R. bifrons in the Missouri flora have been located.