Eastern Poison Ivy vs Japanese Creeper
These plants are often confused when young as both can have three leaflets and a vining growth habit. Older plants are usually easy to distinguish, and any plants can be told apart by climbing method and details of leaf shape.
Eastern Poison Ivy (Toxicodendron radicans) | Japanese Creeper (Parthenocissus tricuspidata) |
A perennial woody vine that can cause an unpleasant and dangerous allergic reaction following contact with its sap. Widespread and abundant in much of its range, and highly variable in appearance. | A deciduous woody vine native to east Asia, introduced in North America. Established in numerous scattered locations, mostly around urban areas. It is a close relative of the native Virginia creeper. It is named for its cultivation in Boston, an area that was historically too cold to grow English Ivy. It is historically the ivy of the "Ivy League". |
 Middle leaflet's stem is conspicuously longer than that of side leaflets. Photo © Shawn Treelife, Public Domain. |  Middle leaflet has no stem or a short stem not much longer than that of side leaflets. Photo © , CC BY-SA 4.0. |
 Climbs via aerial rootlets, which proceed from anywhere along the stem. Photo © mefisher, Public Domain. |  Climbs via tendrils with adhesive discs on the tips. Tendrils only proceed from nodes, points where leaves or branches are attached to the stem. Photo © R. DN., CC BY 4.0. |
 Leaf margins irregularly toothed or lobed, sometimes entirely smooth, sometimes deeply lobed. Photo © botanygirl (iNaturalist), CC BY 4.0. |  Leaf and leaflet margins regularly serrated, never smooth. Leaflets never deeply lobed. Simple leaves unlobed or 3-lobed. Photo © , CC BY-SA 4.0. |
 All leaves are compound with three leaflets. Photo © , CC BY-SA 4.0. |  Plants can have both compound (trifoliate) and simple leaves. Some leaves have two side leaflets fused to create a two-leaflet leaf. Photo © , CC BY-SA 4.0. |
References & External Resources
These short lists show only links helpful for ID. For a complete list of references and resources also covering other aspects of ecology, visit the links section of the full article on each plant, which is the first entry here.
