Pinguicula

Day 279: There is a good reason that Pinguicula vulgaris (Butterwort) is relatively uncommon in western Washington: it prefers an alkaline habitat. There are only a select few places where it can find a suitable ecological niche because our Pacific Northwest environment is largely acidic, thanks to its heavy cover of evergreen trees. In this case, it's growing on a vertical rock face where fir needles are not likely to accumulate. Presumably its substrate rock is of alkaline composition, which in this case would exclude granodiorite, andesite or basalt. Butterwort is an insectivore which captures insects by means of a sticky secretion on its leaves. When an insect is trapped by the mucilaginous "glue," its struggles trigger the release of a digestive enzyme contained in specialized glands. Exoskeletal remains of insects can often be seen as black dots on the yellow-green foliage.