With flowers as lovely as this one, it’s hard to believe it is classified as a noxious weed. It seems all of my favorites are either poisonous or invasive to the native flora but I’m slowly learning the difference between them and the good guys and trying not to feel too sad that they really need to go.
Common Name: White Top or Hoary Cress
Scientific name: Lepidium draba
This plant originates from the former USSR, Afghanistan and Iran. It’s a deep rooted perennial mustard that is highly competitive and because of it’s extensive root system it’s capable of spreading out 12 feet from a single plant in it’s first year (12-20 in it’s 2nd year)! Despite it’s tenacity, it can be effectively controlled by hand pulling or by herbicides.
It’s very important that cattle don’t graze on White Top because it contains glucosinolates which are toxic to them and can cause the females to product tainted milk. Also, the seeds will pass through the digestive system and can spread infestations in an entire pasture. Yikes!
If you are interested in learning more about this plant there is a whole team of international scientists looking for solutions to control this species: http://www.sidney.ars.usda.gov /hoarycress/index.html