Vaccinium is a genus in the Heath family of Ericaceae, and includes huckleberries, cranberries, lingonberries, bilberries, and of course blueberries. Like most other ericaceous plants, they are generally restricted to acidic soils. The Cyanococcus sect of the vaccinium genus includes many different species of blueberries typically found all across North America, including the New Jersey blueberry, the hillbush blueberry, and the local Canadian blueberry that is known to occur within parts of Washington state.
Have a stroll through the park, check out the local gardens, and say Hi to the people who tend to them. Cache is a little out of the way and in a relatively well set-aside area of the park. Be mindful of joggers.
Congrats to Makana50 and Geocachegirl6 for the joint FTF.