Article: Rubus strigosus

Rubus strigosus systematics

Many taxonomists believe that R. strigosus Michx. is the same species as the European Rubus idaeus L. These two are the most common members of the subgenus Idæobatus and can be difficult to differentiate; the most distinctive physical difference being the gland-tipped hairs on primocanes, petioles, pedicels and calyces of R. strigosus as identified by L.H. Bailey (1945). This character had been refuted by Fernald (1900) previously, but Bailey's sheer volume of taxonomic work with Rubus is probably more reliable (see Bailey, 1945; Whitney, 1978). Rubus strigosus is widely distributed in North America, but also through Asia east from the Aerhtal Shan (Altai) Mountain Range in Mongolia to Dongbei (Manchuria) and Japan (Fernald, 1900) where it is thought to have originated along with a great deal of the North American flora (Gray cited in Fernald, 1900). The two species probably recently diverged from a common ancestor and this has lead many taxonomists to refer to them interchangeably or sometimes as a variety of the other such as R. idaeus L. var. strigosus (Michx.) Maxim (Fernald, 1919; Hodgdon and Pike, 1964). Herbarium specimens I examined at the University of Guelph, Waterloo and Dalhousie University and those seen in the field all seem to possess the gland-tipped hairs on the calyx although many were labelled R. idaeus. The plant is named R. strigosus in the floras of Nova Scotia and New Brunswick (Roland and Smith, 1983) and by other maritime field researchers (Nickerson and Hall, 1978; Freedman, 1989) and I agree with their treatment.

-adapted from the thesis "The Dynamics of Rubus strigosus (Michx.) in Post-Clearcut Mixedwood and Softwood Forests of Nova Scotia" published, October 1992 by the author (Terry Grignon)