When it comes to dogwood (Cornus), all the native trees in California have white bracts (flowers) while those in the east are pink. So, if you see a pink dogwood anywhere in California, it is a transplant from the eastern U.S.
In Yosemite Valley, a few pink-flowering dogwood (cornus florida) were planted by residents and have been allowed to remain growing in the park. One at The Ahwahnee is often confusing to park visitors because of the pink color tinting its stems and showy red fruit.
In springtime, eastern dogwood have profuse displays of pink bracts. They look like flowers, but they’re not. Bracts are leaves which have evolved to appear to be flower petals. They help in attracting pollinators. The dogwood’s actual flowers reside at the center of the bracts and have their own modest petals.
Pacific dogwood (cornus nuttallii) are beautiful in their own right and the banks of the Merced River are lined with these flowering white trees in May.
So, if you happen to see a pink dogwood in Yosemite National Park, it doesn’t belong there. And, if you think otherwise, then you’re just barking up the wrong tree.