In message , Nick Maclaren
writes

In article ,
Steve Wolstenholme writes:
| On Mon, 15 Oct 2007 23:56:47 +0100, Sacha
| wrote:
|
| While at Marwood Hill today, we saw a small tree with unbelievably horrible
| thorns! All I remember of the name (I had nothing to write on) was that it
| ended in Americana. The thorns were shaped like hooked rose thorns but a
| great deal larger and were all up the trunk and along every branch
| and twig.
| I've never seen such a brute but I should think it's a security
| firm's dream
| plant. Does anyone know what it might be?
|
| Prunus americanum ?

Hooked thorns on the stem? I have never heard of a Prunus like that,
but don't know that plant.

"The plant’s numerous stems are grayish and become scaly with age; its
branches are more or less spiny with sharp-tipped twigs." (Sounds rather
like a blackthorn, but I have the impression that the American plum is a
larger plant.)

The description rings a bell but, if I recall, it is a primarily
sub-tropical genus. Again, if I recall, it isn't all that fast
growing in most of the UK and tends to be an open tree rather than
forming a thick shrub.


The first thing that comes to mind as American and viciously thorny is
the honey-locust, Gleditsia triacanthos. A Google search gives two
references to Gleditsia americana, one in Ecology 12(2): 259-298 (1931),
but IPNI doesn't mention that name. Nor do the spines match the
description.

The description might be that of Colletia armata.




Regards,
Nick Maclaren.



--
Stewart Robert Hinsley