Perennial sprawling shrubs with herbaceous canes, or rarely woody climbers; stems often biennial, arching, rooting where the tips touch the ground, armed with straight or hooked prickles, glabrous or pubescent. First year growths ('primocanes') usually do not bear flowers; second year axillary growths ('floricanes') bear flowers and fruit. Leaves alternate, usually digitate or pinnate, rarely simple; those on primocanes mostly 5-foliolate; those on floricanes mostly 3-foliolate or simple; leaflets toothed or lobed; stipules narrow, persistent, free or basally adnate to petiole. Inflorescence terminal or axillary, racemose, cymose or paniculate, rarely flowers solitary; bracts present; epicalyx absent; sepals 5, often reflexed; petals 5, spreading, usually white or pink; stamens numerous; carpels few-many on an elongated convex receptacle, ovules 2 (1 aborts) per carpel. Fruit compound, an aggregate of small juicy (rarely dry) drupelets.
About 250 species, cosmopolitan but chiefly in north temperate regions; c. 34 species (10 native) in Australia, in all States except the Northern Territory.
Taxonomy of the introduced members of the genus is difficult due to non-sexual seed formation (pseudogamy and apomixis), polyploidy and hybridization. In Flora Europaea (Tutin 1968), the Rubus fruticosus L. species-aggregate, with its associated 2000 or so named taxa, has been arranged into 66 relatively widespread and distinct micro- or circle-species around which many of the remaining less easily defined species are grouped. These micro-species can only be determined with confidence if material of both primocanes and floricanes is present. Leaf characters in the key and species descriptions apply only to primocane leaves unless otherwise stated.
Barker, R.M.; Barker, W.R. (2005). Blackberry. An identification tool to introduced and native Rubus in Australia., State Herbarium of South Australia, Adelaide.
Evans, J.K.; Symon, D.E.; Whalen, M.A.; Hosking, J.R.; Barker, R.M. & Oliver, J.A. (2007). Systematics of the Rubus fruticosus aggregate (Rosaceae) and oher exotic Rubus taxa in Australia, Australian Systematic Botany 20: 187-251.