They can be differentiated from poison ivy by their five leaflets (Figure 13) young leaves can have only three leaflets. inserta) – These are both woody vines that can be found throughout most of Michigan. Virginia creeper and thicket creeper ( Parthenocissus quinquefolia and P. Wild raspberries and other brambles often have prickly stems, serrated leaves or both acaulis and pubescens) do not have prickles, but they have finely serrated leaf margins, also unlike poison ivy. Wild raspberry and other brambles ( Rubus spp.) – While there are several raspberry and blackberry species found in Michigan that have compound “leaves of three,” most have prickles along the stem (Figure 12), unlike poison ivy.
Boxelder seedlings and trees have opposite leaves (paired), unlike poison ivy.
Boxelder seedlings often have leaves composed of three leaflets but as more leaves emerge, they have five (sometimes seven) leaflets. At this early stage, boxelder seedlings can still be distinguished from poison ivy because their leaves are arranged oppositely, meaning two leaves or branches come from each node (Figure 11), compared to the alternate arrangement of leaves on poison ivy.įigure 10 (first). Boyer)īoxelder tree seedlings ( Acer negundo) – Seedlings of boxelder trees can have compound “leaves of three” at early stages (Figure 10), but then go on to produce leaves with five leaflets (occasionally seven). Opposite (left) and alternate (right) leaf arrangements. It also does not have thorns or spines, nor do its leaves have scalloped or finely serrated margins. It has alternate leaves and never opposite (Figure 9). When reading the following descriptions, please note that poison ivy always has three leaflets and never more than that. Several plant species in Michigan are often confused with poison ivy. The leaves of both Western and Eastern poison ivy turn red in the fall. Some poison ivy plants have “thumb-like” appendages or lobes on the two smaller leaflets, like the specimen here, but sometimes the leaf margins may also be smooth or more toothed.
Note that the margins on this plant are relatively smooth. The leaves of poison ivy are arranged alternately along the stem. Animals such as birds and household pets are not sensitive to the allergen in poison ivy, unlike most humans (see the “Urushiol” section for more information).įigure 6 (first). The berries contain the seeds of poison ivy and facilitate dispersal by birds and other wildlife. These flowers eventually turn into berries that are greyish to white. Mature individuals can also produce clusters of small yellow-green flowers with five petals. Both species frequently produce rhizomes or underground stems, which allows them to spread vegetatively. On each leaf, the two lower leaflets have very short stalks (petioles) and often have “thumb-like” lobes at their bases (Figure 7), while the center leaflet sits on its own longer stalk. Leaflet margins may be smooth, irregularly toothed, or lobed. Leaves are shiny and often dark green, though coloration can vary with growing conditions. Both have compound leaves bearing three leaflets apiece (“leaves of three”), which are arranged alternately along the stem (Figure 6). Both are woody perennials native to Michigan. (Figure 5 photo by Jennifer Yakey-Ault)īesides their architecture, the other features of these two species are similar. Western poison ivy has an upright growth habit with no aerial roots (Figure 4) and can often be seen as patches on the forest floor (Figure 5). (Figure 3 photo by Angela Tenney) Figures 4 and 5 (third and forth). Eastern poison ivy has a vining growth habit and aerial roots to secure it to trees and other objects. Western poison ivy has an upright growth habit (Figures 4 and 5) it does not climb and does not have aerial roots.įigures 2 and 3 (first and second). Western poison ivy ( Toxicodendron rydbergii) can be found in the Upper Peninsula and the northern and western portions of the Lower Peninsula. Eastern poison ivy ( Toxicodendron radicans) is concentrated in the lower half of the Lower Peninsula (Figure 1) and often grows as a vine with aerial roots (Drife, 2015 Reznicek et al., 2011) (Figures 2 and 3). Two different plant species in Michigan are referred to as poison ivy both are members of the mostly tropical family that contains mangoes, cashews, and sumacs: Anacardiaceae.
This is a helpful starting point, but additional details and background are important for identification. radicans, respectively) based on Michigan herbaria records from Michigan Flora Online. Distribution of Western and Eastern poison ivy (Toxicodendron rydbergii and T. We have all likely heard the saying “leaves of three, let it be” in reference to poison ivy.