I came across a stunning variant of the common wild plant cow parsley
(Anthriscus sylvestris) at the Eden project. The variety is called
'Ravenswing', and it has deep red foliage and stems, to the point of almost
being black, but is otherwise the same as cow parsley (same foliage shape,
same white flowers). It looks like a cracking good plant.

I've yet to find a supplier selling seeds for less than three quid a packet,
though, and I'm in two minds as to whether to grow it. On the one hand, it's
beautiful, on the other it's an odd variant of a very common wild plant. Is
it likely to cross pollinate with wild plants? Am I being a drama queen if I
worry about being the cause of a localised outbreak of startlingly different
cow parsley?

Does anyone out there grow this variety? Does it self seed the same colour?
Do the surrounding seedlings of cow parsley also take on the same colour?
Does this deep red variant occur often in the wild anyway?