08/27/2026
Plants of the Mt. Pisgah Summit Trail is a monthly series that highlights plants hikers have spotted and shared through our Summit Trail at Howard Buford Recreation Area project on iNaturalist. Keep an eye out as you explore - if you notice something interesting along the way, you can add your observations too.
For August, weโre featuring Pacific poison oak (Toxicodendron diversilobum), also known as western poison oak.
This woody plant can grow as a low shrub, a dense thicket, or a vine climbing trees. Its leaves are grouped in threes and can have rounded, lobed edges, giving them an oak-like appearance. In late summer, the leaves can turn yellow, pink, or bright red, adding some color to the landscape.
If youโre hiking this time of year, keep an eye out for the colorful leaves - but remember to look, don't touch! Pacific poison oak contains an oil that can cause an itchy rash, and even leafless stems can cause a reaction. You've probably heard saying 'leaves of three, let it be'.
Beyond the color it provides, Pacific poison oak provides food and shelter for wildlife. Deer, squirrels, and other animals eat its leaves, while birds feed on its berries and use the plant for cover.
Native to western North America, Pacific poison oak grows in forests, woodlands, grasslands, and along sunny or shady areas. It is common throughout Oregon and can be found all along the Summit Trail.
Check out what others have been spotting along the trail: https://www.inaturalist.org/projects/howard-buford-recreation-area-flora-of-the-main-summit-trail
Photo Credit from Left to Right:
https://www.inaturalist.org/photos/132536123
https://www.inaturalist.org/photos/305107420 Gail Baker
https://www.inaturalist.org/observations/30714701
https://www.inaturalist.org/photos/630338898
https://www.inaturalist.org/photos/272136067 Wuenschel
