Geometrid moth caterpillar. They are champion camouflagers! Not only do they have the ability blend into their surroundings, their physical strength is incredible! Imagine holding yourself in the same position for 6 hours or more. With the back “legs” (I doubt that is what they are called) adhere to the stem holding the body out like a branch. My guess is this goes on all day until dusk, once the sun begins to set it will once again enjoy the Monkey Flowers (Mimulus ringens) tenders.
I offered her: Black-eyed Susan's, Obendient Plant. Her preference - Monkey Flower
Propagation Notes -
Stratifying Seeds - Cold Moist Storage 60 days - do not cover seeds when planting as they need light to germinate