Gene Newcomb wrote in message ...
Black raspberries (Rubus occidentalis) or blackcaps are a minor crop
here in Oregon. As you say, they do root at the shoot tips like
blackberries, but they are a distinctly different plant with fruits
which detach from the receptacle like the more commonly grown red
raspberry. The color of the stems in the winter is a smoky red-purple
that makes the fields easy to identify then. I don't know whether it is
still true, but one of the main uses of the juice of this fruit was as
the pigment for the grading stamps for meat here in the US. The common
names above are those accepted here in the US. See the book Scientific
and Common Names of 7,000 Vascular Plants in the United States by L.
Brako, A.Y. Rossman and D.F. Farr, APS Press, 1995.

Many thanks.

Mike.