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[/quote]

New member, here, from across the pond but now living in the UK.

You should hope they're selling real black raspberries or "black caps" (rubus occidentalis). Speaking as a New York Stater, I can vouch for their lovely - and quite distinct - flavour. There's no mistaking them for anything else.

In fact, if it turns out Focus is indeed selling rubus occidentalis plants, please let us - or at least me - know. I'll run right out and get some. I'm just now at my parents' place in NYS, where this morning I sampled some black currant / black raspberry jam I made a few seasons ago. Scrumptious. Plus, I just found out that rubus occidentalis is supposed to be very high in free-radical-chasing goodies (alias chemopreventive phytochemicals).

Joanna Sheldon