Hi, these are Arum maculatum, the berries are exttremely poisonous, 1 of our native plants, Derek.

Oh thank you Derek, I'll keep an eye out for them when I'm walking the dog, he's into anything he can put in his mouth. I'm glad you told me they're poisonous.

There are a lot more plants and seeds that are poisonous but I would be very surprised if your dog would get his mouth anywhere near those berries!