Mycology

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

All info via eol and here

Any corrections please post in comments and I'll edit my post