The woman I live with has been buying plants. Not one or two. Many. They arrive in small pots and get arranged on surfaces I consider mine. I have been investigating which of them are a problem. The answer is: more than she realises, and more than I would like.

It is important that I am precise about this rather than alarming. It is a serious matter. Lives are at stake. But relax, not every plant is dangerous. Some are entirely fine. A spider plant, for instance, has a mild hallucinogenic effect on cats that I am told some find appealing. I have no particular comment on this. The point is that it is not going to harm you. There is a difference between a plant that is fine, a plant that causes irritation, and a plant that requires a vet immediately. That distinction matters and most people do not make it clearly enough.

One of the most serious indoor plants on this list is the peace lily. It is very common, sold everywhere, frequently described as a good beginner plant, and it is toxic to cats. All parts of it. Oral irritation, excessive drooling, difficulty swallowing, vomiting. In significant quantities, more serious effects are possible. We had one of these once. I sat next to it on the windowsill for longer than I would now consider advisable.

Pothos is equally widespread and similarly problematic. The leaves and stems contain calcium oxalate crystals. Contact with the mouth causes immediate and intense irritation. It is a trailing plant, which means it hangs at exactly cat height, which seems like a design oversight.

Philodendron is the same family, same crystals, same effect. There are dozens of varieties, and they are all over the interior design content the woman I live with looks at on her phone.

Aloe vera is kept in many kitchens for its supposed medicinal properties. It is toxic to cats. The gel inside the leaves contains compounds that cause vomiting and lethargy. I mention this because it tends to sit on sunny windowsills, which are, self-evidently, where I am.

Dieffenbachia - sometimes called dumb cane - causes severe oral irritation and in large quantities can cause swelling that affects breathing. I do not want to be dramatic about this, but I also do not want to understate it.

Sago palm is sold as an indoor plant and is extremely toxic. All parts, but particularly the seeds. Liver failure is the risk. Oh goodness, liver failure! This plant should not be in a home with cats under any circumstances.

The woman I live with has a pothos and two philodendrons. She did not know any of this until I began my investigation. She knows now. The pothos has been moved to a high shelf, which she considers a solution. I consider it a temporary measure, as I am fully aware of the high shelf.

I have made a note of its location and will monitor this. I have direct line to George if things get hairy.