In message , Nick Maclaren
writes

In article ,
Stephen writes:
|
| Focus DIY stores are selling what they call a "black raspberry". Has
| anyone heard of these? What are they? What is the difference between a
| black raspberry and a blackberry?

They are different, but related, species. A black raspberry will
be a purplish raspberry - just that.


Regards,
Nick Maclaren.

Botanically raspberries are subgenus Idaeobatus and blackberries are
subgenus Rubus (aka Eubatus). Rubus leucodermis and Rubus occidentalis
are black-fruited American raspberries, but whether one of these is what
Focus are selling, instead of a variant of Rubus idaeus, or a hybrid of
some description, I can't say. (Wikipedia tells me that the American
black raspberry has its own taste, distinct from both that of the
European raspberry and that of the blackberry.)

I don't know what the botanical characters are which separate the
subgenera, but horticulturally raspberries and blackberries have
different habits. Raspberries produce erect fruiting canes and spread by
rhizomes. Blackberries have a mounding or rambling growth habit, and
spread by tip-rooting.
--
Stewart Robert Hinsley