Not that you're not necessarily going crazy, but they are in fact related, in the botanical family Ericaceae. I've written before about binomial nomenclature in horticulture, distinguishing between the different species within a common genus. Now, we're talking about different genera (plural of genus) within the next higher group, the family.
While Karl Linnaeus gets most of the credit for his systematic classification of things great and small, the idea of biological families actually comes from one of Linnaeus' contemporaries, French botanist Pierre Magnol. Families tend to be named for one of their genus that typifies the group on the basis of some physical characteristic (e.g. flower structure). In these cases, the suffix "-aceae" simply gets tacked on to the stem of the botanical genus name. Thus, the genus Rosa (i.e., the rose) was determined to be representative of a group of plants with common reproductive characteristics, so that group was given the family name Rosaceae (pronounced "rose-ACE-ee-ay". Other families include:
- -Aquifoliaceae (named for the aquiline leaf margins of the holly, the only living genus in this family)
-Caprifoliaceae (named because the leaves resemble the cloven hooves of goats)
-Graminaceae (the grass, or grain (grass seed), family)
-Leguminaceae (the legume or bean family, aka Fabaceae (think fava beans)
(Because the Rosaceae tend to produce delicous fruits — from rose hips to apples, pears, stone fruits, strawberries, almonds — as well as flowers that stir the soul, one of my favorite instructors Quin Ellis was fond of saying that the grass family may have set the dinner table for civilization… but the rose family provided dessert.)
If you want to geek out on this even more than we already have, the Department of Biology at St. Louis University has a very nice discussion of biological nomenclature; for the "lite" version, see the Dummies Guide. But back to the humble blueberry: its family Ericaceae also includes, not surprisingly, cranberry and huckleberry; the aforementioned Arbutus and its cousin Arctostaphylos (manzanita); azaleas and rhododendrons; and the eponymous Erica, genus of heaths and heathers. And while I noticed the similarities between the flowers, in fact the most common trait is the foliage structure: smooth-edged, single leaves arranged alternately along the stems. (Good thing, too: to develop a more robust root system and better fruit yields, I strip the flowers off for the first three years.)