Poison sumac is a woody shrub that can cause an irritating, potentially dangerous rash upon skin contact. Learning how to identify poison sumac is important to avoid coming into contact with this hazardous plant. With some knowledge of poison sumac’s distinguishing features and habitat, you can stay safe when spending time outdoors.
Introduction to Poison Sumac
Poison sumac (Toxicodendron vernix) is a shrub or small tree that commonly grows in wetlands throughout the eastern and southern United States. All parts of the plant, including the stems, leaves, roots and berries, contain urushiol – an irritating oil that causes an itchy, sometimes painful rash upon skin contact in most people.
The rash, known as urushiol-induced contact dermatitis, develops 12-48 hours after exposure and can last 1-3 weeks. In severe cases, the rash may spread over large areas of the body and develop into fluid-filled blisters. Around 10-20% of people lack sensitivity to urushiol and will not react upon contact with poison sumac.
Identifying poison sumac is crucial to avoid accidental exposure while hiking, camping, hunting or participating in other outdoor activities where the plant may be encountered. If you do come into contact with poison sumac, promptly wash the exposed skin with soap and cool water to dilute the urushiol before it penetrates into the skin.
Distinguishing Features of Poison Sumac
Poison sumac has several distinguishing features that can help identify it:
Leaf Arrangement and Shape
Poison sumac leaves are arranged in paired opposite rows along the stem. The leaves are pinnately compound, consisting of 7-13 smooth-edged leaflets per leaf. The leaflets are 2-6 inches long, oval or oblong in shape, with pointed tips.
Leaf Color
The leaves are bright green in spring and summer, turning vivid red or orange in the fall. The leaf stems are red.
Flower and Fruit
Poison sumac flowers are small, yellowish and grow in drooping clusters up to 6 inches long. The fruits are whitish, waxy drupes, each containing a single seed. The fruits hang in loose clusters, ripening to gray.
Stem and Bark
Young poison sumac stems are smooth and reddish, while older bark is light gray and lightly ridged or furrowed. The stems are upright, averaging 6-15 feet tall, but can sometimes grow as high as 30 feet.
Growth Habitat
Poison sumac grows exclusively in wet soils, commonly found in swamps, bogs, fens, wetlands, marshes and floodplains. It is often found along the borders of lakes, ponds and streams. Poison sumac tolerates partial shade but prefers full sunlight.
Differences Between Poison Sumac and Lookalikes
Poison sumac is often confused with other plants, both harmful and benign. Knowing how to distinguish it from lookalike species can prevent accidental exposure.
Poison Ivy
Poison ivy is the plant most commonly mistaken for poison sumac, and with good reason – both plants contain toxic urushiol and cause identical rashes. However, poison ivy is a climbing vine rather than an upright woody shrub. The leaflets are smooth or toothed edged rather than smooth edged, and poison ivy has only 3 leaflets per leaf compared to 7-13 for poison sumac.
Staghorn Sumac
Staghorn sumac (Rhus typhina) is sometimes mistaken for poison sumac, but it is harmless. Staghorn sumac leaves have a furry underside, giving them a velvety texture, while poison sumac leaves are smooth on both sides. The fruits of staghorn sumac are fuzzy, red drupes, unlike the smooth, whitish fruits of poison sumac.
Alder Trees
Alders are small trees with pinnately compound leaves that superficially resemble poison sumac. However, alder leaflets have small teeth on the edges, while poison sumac leaflets are smooth edged. Also, alders do not contain urushiol and are completely harmless.
Elderberry
Elderberry (Sambucus species) is a small tree or shrub with pinnately compound leaves, sometimes leading to confusion with poison sumac. However, elderberry leaflets are much more finely toothed along the edges compared to poison sumac’s smooth leaflet edges. The fruits are small purplish-black berries rather than whitish drupes.
How to Identify Poison Sumac (with Pictures)
When spending time outdoors in areas where poison sumac may grow, keep an eye out for the following distinctive features to positively identify and avoid the plant:
Leaflets in Paired Rows
Look for pinnately compound leaves with 7-13 oval leaflets arranged in opposite paired rows along the stems. Poison sumac will not have triple leaves like poison ivy.
Smooth Leaflet Edges
Examine the leaflets closely – the edges should be smooth, without serrations or teeth. This helps distinguish poison sumac from lookalikes like staghorn sumac and alders.
Red Leaf Stems
Check the color of the leaf stems. Poison sumac leaf stems are bright red, while the stems are green on plants like elderberry.
Upright and Woody
Look for a shrub or small tree growing upright to heights of 6-15 feet, with woody, rigid stems. Poison sumac has an upright, woody growth form rather than a trailing vine.
Growing in Wet Areas
Only search for poison sumac in moist habitats like marshes, swamps, bogs and floodplains. It does not grow in dry or well-drained soils. Habitat is a good clue to eliminate lookalikes like poison ivy that occupy drier areas.
Red Twigs
The youngest stems and branches are smooth and reddish in color, helping distinguish poison sumac from other wetland shrubs.
Clustered White Berries
Scan for drooping clusters of waxy white fruits. Mature poison sumac berries are grayish-white, unlike the red fruits of staghorn sumac.
By recognizing these characteristic features of poison sumac, you can identify the plant in the wild and avoid hazardous contact. If you do touch any part of poison sumac, wash your skin immediately with soap and cool water. Prompt washing prevents a rash in most cases by diluting the urushiol before it can penetrate into the skin. With proper identification and precautions, poison sumac can be avoided in areas where it grows.
Frequently Asked Questions About Poison Sumac Identification
How do I know if I touched poison sumac?
If you come into contact with any part of poison sumac, you likely will develop an itchy rash with reddened patches and possibly fluid-filled blisters within 12-48 hours. The rash may progress to cover large areas of the body. Symptoms usually last 1-3 weeks and can be serious. Seek medical attention for severe rashes.
Does poison sumac also cause respiratory issues?
No, poison sumac only causes skin irritation, unlike poison ivy which can additionally cause respiratory problems if burned. Poison sumac smoke is not toxic and does not cause breathing issues. The urushiol oil is only present on the plant surface and does not volatilize.
What does poison sumac rash look like?
The rash begins as extremely itchy, reddened patches that can develop into seeping blisters. It spreads over hours to days, often becoming worse before healing. The rash may cover areas that did not directly contact the plant due to spread via clothing or when urushiol is carried on the hands to other body parts.
Can I get a rash from touching animals that contacted poison sumac?
Yes, your pet can transfer poison sumac oil to you after brushing against the plant. Use gloves and soap when washing an animal that may have touched poison sumac to prevent secondary exposure. Any objects contacting the plant, like clothing, tools or sporting equipment, can also transmit urushiol.
Does poison sumac grow in my area?
Poison sumac only grows in swamps and very wet soils in the eastern and southern United States, ranging from Maine to Minnesota in the north, and Florida to eastern Texas in the south. It does not grow west of the Rocky Mountains. Consult range maps to see if poison sumac grows in your location.
What time of year is poison sumac most hazardous?
Poison sumac is most dangerous in late summer and fall when urushiol levels peak in the plant’s stems and leaves. The shiny white berries also contain very high urushiol concentrations. Exercise caution around poison sumac from mid-summer through the fall season when the plant is most toxic.
Conclusion
Identifying poison sumac is vital when spending time outdoors in areas where this hazardous plant grows. Learn to recognize the shrubby growth form, compound leaves with smooth-edged leaflets in paired rows, red twigs and stems, and clusters of whitish berries. Habitat is a great clue, as poison sumac only grows in very wet soils. Distinguish poison sumac from benign sumacs and other wetland shrubs by the combination of pinnate leaves, smooth leaflet edges, upright orientation and wet habitat. Promptly wash skin upon potential contact to prevent a rash. With knowledge of its identifying features, you can spot poison sumac before accidental exposure occurs. Stay safe outdoors by learning how to identify poison sumac using its distinct characteristics.
How to Identify Poison Sumac (with Pictures)
Introduction
Poison sumac (Toxicodendron vernix) is a woody shrub that grows exclusively in wet soils and swamplands in the eastern and southern United States. All parts of the plant contain urushiol, a potent oil that causes an itchy, irritating rash upon skin contact in most people. Learning how to identify poison sumac is crucial for hikers, campers and outdoor enthusiasts to avoid brushing against this hazardous plant.
Poison sumac has several distinctive features that aid identification:
Distinguishing Features of Poison Sumac
- Pinnately compound leaves arranged in opposite pairs along the stem
- 7-13 smooth-edged leaflets per leaf
- Leaflets are oval or oblong with pointed tips
- Bright green leaves in spring/summer, turning red in fall
- Small yellowish flowers in drooping clusters
- Whitish fruits in loose hanging clusters, ripening gray
- Upright woody shrub growing 6-15 feet tall (occasionally to 30 ft)
- Young stems are smooth and red, mature bark gray and lightly ridged
- Grows exclusively in very wet habitats like swamps, bogs and marshes
Differences Between Poison Sumac and Lookalikes
Poison sumac is often confused with similar appearing plants, both harmful and benign. Being able to distinguish it from lookalikes can prevent accidental contact and exposure.
Poison Ivy
Poison ivy may be most commonly mistaken for poison sumac, but poison ivy is a vine rather than a shrub. The leaflets are triple rather than paired, and have toothed rather than smooth edges.
Staghorn Sumac
Staghorn sumac is a non-toxic sumac species with fuzzy, velvety leaves that have a serrated edge. The fruits are fuzzy and red, unlike poison sumac’s smooth white fruits.
Alder Trees
Alders have pinnate leaves resembling poison sumac, but the leaflets have small teeth and are not smooth edged. Alders do not contain urushiol.
Elderberry
Elderberry leaves are more finely toothed on the edges than poison sumac’s smooth-edged leaflets. The fruits are purplish-black berries rather than white drupes.
How to Identify Poison Sumac (with Pictures)
When spending time outdoors where poison sumac grows, look for these distinctive identifying features:
Leaflets in Paired Rows
Look for leaves with 7-13 leaflets arranged in opposite paired rows along the stems. Poison sumac will not have triple leaves.
Smooth Leaflet Edges
The leaflet edges should be smooth without serrations or teeth. This distinguishes it from lookalikes like staghorn sumac.
Red Leaf Stems
Poison sumac leaf stems are bright red, while lookalike plants have green stems.
Upright and Woody
Poison sumac grows upright to heights of 6-15 feet, with woody, rigid stems rather than a vining habit.
![Upright poison sumac](https://www.researchgate.net/profile/Frank-Telewski/publication/303814235/figure/fig1/AS:386379081060352@1469855084995/Leaf-of-poison-sumac-Toxic