No interactions present.
sp. is species (singular), spp. is species (plural).
So Prunus sp. would be an a reference to a (presumably unidentified) species of Prunus, and Prunus spp. would be a reference to multiple species of Prunus. Prunus sp. would have been appropriate here.
I will remember of the next time
Lat/Lng: 55.5, -4.4406
OS grid ref: NS459256