Houseplants are a decorator’s best friend, adding pops of color and a vibrant touch to even the blandest home interiors. And studies show that they also improve air quality, lower your stress level, generally make you happier, and just might even make you smarter.

But what if those seemingly innocent buds are doing just the opposite? What if they’re actually trying to kill you?  Maybe even your pets?

1. Oleander
Every part of it is poisonous. Ingesting it can cause a range of symptoms, from dizziness to vomiting, and may even lead to death (especially in the case of pets and small children).

2. Peace lily
It’s poisonous both for humans and for pets. Ingestion can cause skin irritation and swelling, trouble speaking, and burning. Doesn’t sound like “peace” to us.

3. Sago palm
While humans may only suffer some discomfort if they ingest it, the plant is extremely dangerous to dogs. (In fact, sago palm poisoning is the No. 1 reason for calls to Animal Poison Control in South Carolina.)

4. ZZ plants
They’re also noxious to humans and pets. While not as dangerous as oleander, we probably wouldn’t keep any around if we had curious kiddos.

5. Snake plant
Large doses can cause nausea and vomiting, and the poison found in the plant has a numbing effect that can cause the tongue and throat to swell. The plants are more toxic to dogs and cats, which can suffer from nausea, vomiting, and diarrhea.

6. Lilies
While not generally dangerous to humans, all lilies are highly toxic to cats. And if a lily gets ingested by your kitty, it can lead to kidney failure and even death.