The genus Rubus (Rosaceae) is one of the most challenging groups of plants with respect to its classification and evolutionary history. Rubus comprises between 429 and 750 species grouped into 12 subgenera.  It occurs primarily in northern temperate regions, but can be found on all continents except Antarctica.  The genus is economically and ecologically important as fruit crops (e.g., raspberries, blackberries, cloudberries), ornamentals, food for wildlife and indigenous peoples, invasive weeds, and in early forest succession. 

Rubus is considered taxonomically complex because of frequent hybridization, great morphological diversity, vegetative propagation, agamospermy (asexual seed production), and high incidence of polyploidy (more than two copies of each chromosome per cell).  Approximately 60% of all Rubus species are polyploid, and hybridization is known to occur between closely related species and, in several instances between members of distantly related groups.  Given the size, complexity, and importance of Rubus, it is surprising that no comprehensive study of its classification and relationships has been done since 1914.

• Bibliography
• Classification
• Ploidy
• Species A - Z
• Systematics
• Acknowledgments