The opposite of Bailey, Bella will chew on anything & everything; edible or not. Luckily, Christmas and Easter Cactuses are not poisonous to dogs. I checked.

"The Christmas Cactus (or its relative, the Easter Cactus) plant is not toxic to dogs in either its parts or flowers. However, fibrous plant material can cause irritation to the stomach and intestine, leading to vomiting or diarrhea."

I try to ONLY allow Bella to sample truly editable flowers (for both pets & humans).
That limits the variety of plants on my deck.

Meanwhile, I know I also can't keep Bella in a total bubble. Although I wouldn't allow her to put the Easter Cactus in her mouth, I did allow her to sniff it. I knew that if she was quick and unexpected grabbed a flower, that wouldn't hurt her. She didn't. She just sniffed; like Bailey does.