I have 2 new weeds in my yard this year.  I haven't seen either of them before.  One has long trailers with starburst like leaves every few inches.  The stems are green with a red stripe.  The stems are sticky and also slightly prickly.    

The second weed is a very pale green. The stems seem to be hollow and the leaf formation is sort of of a long rocket shape with a "pointy" top.