Ophiocordyceps clavulata is a fungi parasite of scale insects feeding on trees including Pignut Hickory and American Hazel. It grows up to 4 mm
From the very limited information on the internet it's usual habitat is North America and Canada, but has also been recorded in Sweden
All photos via eol
Any corrections please post in comments and I'll edit my post
I'm going to do a 'mega post' or smaller of the cordiceps that infect insects over on awwnverts probably this coming week
They're fascinating things in a somewhat horrifying way, and lots of lovely photos to be discovered!
Nice, gonna look forward for it this week.