I took this photo yesterday of Myrtle Spurge, aka Donkey Tail Spurge (Euphorbia myrsinites), spreading aggressively in the Boise Foothills. This attractive attractive pest was once considered a great choice for xeric landscaping, but its drought-tolerance and ease of propagation has allowed it to jump into the wild. A native of Eurasia, it can easily overwhelm native competitors and is now listed as a noxious weed in Colorado, Oregon and some Utah counties. It is probably too late to prevent it from taking over large areas of our Foothills, but we should still avoid it in our landscapes. Always wear gloves when yanking it out–the stems contain a nasty, milky sap.