I will pass on a bit of info I learned years ago. In one of the women's magazines in the 60-70s like Women's Day/Family Circle I read where airplane plants were a good indicator of carbon monoxide from furnaces. Shortly after reading that warning, I noticed an airplane plant I had just purchased kept having brown leaves, even though I was watering it faithfully. I remembered that article and had our furnace checked. There was a cracked heat exchanger that was allowing carbon monoxide to escape. The inspector immediately shut down the furnace. The crack was hard to see until they took the part out and showed us where it was. The furnace was a good brand and only 9 years old, so we didn't expect any problem with it.

Since then, I've always had an airplane plant in my house.

Thanks for the info about the carbon monoxide!

and how fortunate that you read that helpful bit in a woman's magazine.

It is all the more extraordinary that the furnace was a good brand and not that old.

I have Boston ferns in my bedroom--three of them--as I understand they purify the air.

am going to take cutting and root them. I already did one and gave it away, but would love to have a whole row of prayer plants in one window! Wish me luck I am a beginner in this.