The botanical highlight of a weekend trip to the Hurricane Ridge area of Olympic National Park was seeing these plants in the wild for the first time. The second carnivorous plant to be featured on Botany Photo of the Day (if memory serves me correctly), California butterwort or horned butterwort is amphiberingian in its distribution, i.e., it is found on both sides of the Bering Sea. Specifically, the taxon is native to Japan in Asia and northern California to Alaska in North America.
Carnivory is a relatively rare phenomenon in flowering plants, occurring in roughly 0.2% of all taxa. In the case of butterworts, the trap used to capture insects is a “flypaper trap” – a sticky, mucilaginous leaf surface. Imagine trying to walk through glue and you’ll have an idea of what the insects encounter. The little black spots on the leaves clearly seen in the first photograph (and artistically out of focus on the second) are insects in various states of being digested. Like most carnivorous plants, Pinguicula vulgaris subsp. macroceras grows in an environment where it is either nutrient-poor or difficult to uptake nutrients, so the evolution of carnivory has given it the ability to source nutrients (especially nitrogen) from elsewhere.
Wikipedia has an excellent entry on carnivorous plants if you’d like to learn more, including a close-up photograph of a Pinguicula leaf surface.