Purple coneflower or Echinacea is an easy one to spot as it looks like a pink droopy daisy. I dig up the roots and use them as an immune system booster and a natural antibiotic.
White sage is another simple find...it looks from a distance as you come up upon it like grey grass. My Lakota friends use this herb all year long in sweat lodges and Yuwipi ceremonies.
Compass plant looks like a number of yellow daisies all hugging a single stalk, each facing the same direction. The root of this native weed is HUGE, oftentimes bigger around than an adult thigh, and takes a lot of digging just to get a good chunk. (Sometimes I'm tempted to bring an axe to help harvest this one.) I cut up and dry the root in finger sized pieces and when I have a headache, I take a lighter to burn a bit of the end of the dried root to inhale the smoke before going to lay down for half and hour. For me it works at about the same speed as asprin.