[The Sumac Family in the Columbia River Gorge of Oregon and Washington]

Pacific Poison Oak - Western Poison Ivy Hybrid

Toxicodendron diversilobum x Toxicodendron rydbergii

Pacific Poison Oak - Western Poison Ivy Hybrid: Toxicodendron diversilobum x Toxicodendron rydbergii - Pacific Poison Oak - Western Poison Ivy Hybrid: Toxicodendron diversilobum x Toxicodendron rydbergii

Pacific Poison Oak - Western Poison Ivy Hybrid: Toxicodendron diversilobum x Toxicodendron rydbergii - Pacific Poison Oak - Western Poison Ivy Hybrid: Toxicodendron diversilobum x Toxicodendron rydbergii

Examples of what appears to be hybrids of pacific poison oak and western poison ivy as seen along the old Klickitat County Dump Road alongside Eightmile Creek above the Crawford Oaks Trailhead at Columbia Hills Historical State Park......November 2, 2022. Note the acute leaf tips and mostly entire leaf margins, characteristics of poison ivy. Note also the sprays of berries which are pendant with some leaf margins having broad, rounded teeth or short lobes, characteristics of poison oak. Plants at this location are both shrubs and climbing vines as seen in the photos.

Fall foliage of Pacific Poison Oak - Western Poison Ivy Hybrid: Toxicodendron diversilobum x Toxicodendron rydbergii - Fruits of Pacific Poison Oak - Western Poison Ivy Hybrid: Toxicodendron diversilobum x Toxicodendron rydbergii

Fall color of a poison ivy-poison oak hybrid at left from Crawford Oaks, Columbia Hills Historical State Park...........2013. The photo at right shows the fruits of of a poson ivy-poison oak at right from Crawford Oaks, Columbia Hills Historical State Park...........October 31, 2020. Note that on this plant, the fruits are held in a compact, largely erect sluster with somewhat spreading and pendant side branches.
Paul Slichter