From the CO2Science archive: Krameria erecta is found in the US Southwest and Mexico where it positively thrives on extreme heat and dryness. It likes short, mild winters and long hot summers so we aren’t going to see it in Ontario, which is sad because it is a very pretty little shrub. But for those living in the sorts of places where Littleleaf Rattany grows, you are in for more of it. In 2006 there were two experiments showing that an extra 300 ppm CO2 resulted in an extra 102.5% growth. So heat, dryness and more CO2, far from being an existential threat, are just what Krameria erecta is hoping for as it strives to become Bigleaf Rattany.