When you think of PA native trees, oaks, maples, and hemlocks usually take the spotlight. Here's 5 native trees you may not have known about! Oxydendrum arboreum - Sourwood Oxydendrum arboreum, or Sourwood, is deer resistant and grows to be 20-50 feet tall at maturity. Did you know that they call this tree "Sourwood", because the leaves and branches contain oxalic acid which makes them actually sour! In mid to late summer when most other trees have finished blooming, sour