From the CO2Science archive: We don’t know if the lady is spotted and the plant looks like her thumb, or the plant looks like a lady’s thumb except that it is spotted, or someone just spotted a lady’s thumb. But anyway it doesn’t look like the thumb of any lady we’ve met, spotted or not, and if it did she should consult a physician without delay. Moreover it’s also known as Jesusplant, and looks even less like Him, and as Redshank which is likewise no help because the flowers are pink. Its Latin name is Persicaria maculosa but also Polygonum persicaria, making our confusion complete. But this spotted lady’s digit will enjoy the ongoing rise in atmospheric CO2. In 1995 a pair of experiments showed an additional 300 ppm CO2 resulted in an extra 38.2% growth.