How do you call this?

nœud (knot)

butthole

Sučok (small Suk, 'bough')

I didn't know there was a name for that
I'd just call it that dark spot

Wood eye

Wow Americans are very funny

its a cut branch in cut wood

Oksa (branch)

knot

idk, oksakoht (place of branch)

vghhh my brother...