Scorzonera hispanica is the black salsify

There are several - if you google it, you'll find them. I'm not sure which name you're looking for. It's apparently known as the 'Vegetable Oyster'

It's in the genus Tragopodon which is part of the aster family, so when you eat salsify you are eating the root of an aster flower. The beautiful purple flowers are borne in the morning and only last a few hours. They are followed by the dandelion like seed heads with the seed floating off in the wind.
Rather than just eating the root, which can be difficult to get to grow straight and thick, you can also pick and cook the immature seed heads which have a nice unusual taste.
Scorzonera is also a member of the aster family but has a yellow dandelion like flower.
'Vegetable oyster' is a ridiculous name as it tastes nothing like any oyster I have ever eaten!
However, eaten with a white sauce the root is a really good taste, unique I'd say.

I agree Bertie nothing like an oyster!

Nice roasted with the Sunday joint too!

Indeed very yummy! Thought were we gastronomes first or gardeners? I know for me it was a gardener!

thank you everybody for your answer