First: Kousa dogwood
Second: Flowering dogwood or Cornus florida.
On both, those “petals” are bracts and the real flowers are those little beady balls they surround.
Our pink dogwoods are susceptible to dogwood anthracnose, a fungus which takes advantage of cool wet spring and fall weather. One way to help your dogwood is to water during drought, mulch around the base and try not to hit it when mowing or weed whacking. Otherwise, the fungus causes die back and the tree gets brown spots and cankers and dead twigs.
Kousa seems less susceptible to anthracnose and powdery mildew, but is affected by scorch: too much sun and dry, hot wind. Again, make sure to water during drought so the tree is less stressed at other times.
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