"Keefiedee" wrote in message
...
We have a fence in the garden of our listed building home, with standard
posts, but boards like I've never seen before. They are 6 feet wide, with
straight vertical edges, but variable in height from perhaps 6" to 9".
Neither horizontal edge is straight, so they have a very rustic
appearance, and they are also tapered like featheredge boarding. They are
clearly very old.

Does that make sense to anyone?

Yep,. sounds like tree trunks have been ripped into
boards and the variable height of the boards is due
to the original tree trunks varying like that.

What are they called? Where could I get them?

No reason why they couldnt be ripped from
new tree trunks of the appropriate size.

They are all pretty much past their sell-by date!