Tag Archives: urushiol

Poison Plants

Poison Sumac Information

Poison Sumac

General:

Poison sumac – Toxicodendron Vernix, grows in swamps, bogs, depressions, and other wet areas. Like both poison ivy and poison oak, poison sumac produces urushiol, a clear liquid compound found within the sap of the plant that causes an itching rash in most people who touch it.
Poison sumac basically manifests itself as a woody shrub or small tree. Unlike both poison ivy and poison oak, poison sumac is not an overly common plant.

Identification:

Poison sumac is a woody shrub or a small, slender tree that measures 5′-20′ tall. The leaves are pinnately compound (meaning – the leaflets grow from several places along the stalk) and alternate along the stem. The plant is deciduous so the leaves fall in the autumn turning brilliant orange to red in color. Each leaf stem contains 7 to 15 leaflets that are usually 2″ to 4″ long and 1″ to 2″ wide, and elliptic

Distinguish poison sumac shrubs from their harmless namesakes and consider the latter for great fall foliage

to oblong in outline. The lower leaf surface is lighter green and the edges are smooth (not toothed). The central leaf stalk is typically reddish colored.

New stems are smooth and reddish, but they gradually turn tan to light gray with age. These light-colored leafless stems can look deceptively like other non-toxic shrubs or trees during the winter. Small greenish flowers are followed by white berries similar to poison ivy.

Location:

As can be seen in the map, poison sumac is found in most of the eastern United States, between Texas and Florida in the south, to Minnesota and Quebec in the north. Poison sumac is generally found in wet soil. The picture above was taken at the University of Michigan – Nichols Arboretum in Ann Arbor, MI. It was on the side of a hill in very wet soil.

Poison:poison sumac distribution is primarily in eastern North America

Urushiol binds to the skin on contact, where it causes severe itching that often develops into a red rash or flesh colored bumps and blistering. The rash can be treated with Calamine lotion or other over the counter remedies such as oatmeal baths and baking soda. In severe cases hospitalization may be required or if the plant has been ingested.

Urushiol oil can remain active for several years, so handling dead leaves or vines can cause a reaction. In addition, oil transferred from the plant to other objects (such as pet fur) can cause the rash if it comes into contact with the skin.

The fluids released by scratching the blisters do not spread the poison or the rash. The fluid in the blisters is produced by the body and it is not by urushiol.

Poison Plants

Poison Ivy – Toxicodendron radicans

Poison Ivy

General:

Poison ivy is a common North American plant that produces urushiol, a clear liquid compound found within the sap of the plant that causes an itching rash in most people who touch it. The fluids released by scratching the blisters do not spread the poison or the rash. The fluid in the blisters is produced by the body and it is not by urushiol.

Poison ivy likes to grow in suburban areas and many people I know have unwittingly cleaned out “weeds” along neighboring fences only to wake up the next day with the signature itchy rash.

Description:

Poison ivy can be found growing in any of the following three forms

Trailing vine that is 4 to 10 inches high

poison ivy generally has three leaves and white berriesShrub up to 4 feet tall

A climbing vine that grows on trees or some other support. Older vines on substantial supports send out lateral branches that may at first be mistaken for tree limbs.

Poison ivy leaves are deciduous and typical form in clusters 3 on their own stem that are almond-shaped. The leaves grow alternately on the main stem. The leaves are not very large – approximately 1 ½” – 5” long. Like other plants that are deciduous, the leaves of poison ivy change color with age and season starting out often times red in spring then to green then red, orange, or yellow in the fall. The stems are smooth – this easily distinguishes poison ivy from blackberry vines.  The leaves as shown by the picture can have slight serrated edges and as the leaf matures can be shiny.

Vines growing on the trunk of a tree become firmly attached through numerous aerial rootlets. One problem here is that poison ivy grows in the same areas as Virginia creeper, so care must be exercised because you will not be able to clearly identify poison ivy in this situation. Poison ivy vines can have a “hairy” appearance, which can help in identification.
Poison ivy flowers from May to July. The flowers are yellowish- or greenish-white located in clusters approximately 3” above the leaves. The berries mature by August to November and are grayish-white in color.

Location:

Poison ivy grows throughout much of North America, including eastern Canada in Quebec, Ontario, Manitoba, and all U.S. states east of the Rockies, as well as in areas of Mexico. So the lesson here is that you can expect it just about anywhere. When out and about hiking or camping you will likely find poison ivy in wooded areas, much of the time in open areas that receive sun. It also grows in exposed rocky areas and in open fields.

Poison:

Urushiol binds to the skin on contact, where it causes severe itching that often develops into a red rash or flesh colored bumps and blistering. The rash can be treated with Calamine lotion or other over the counter remedies such as oatmeal baths and baking soda. In severe cases hospitalization may be required or if the plant has been ingested.
Urushiol oil can remain active for several years, so handling dead leaves or vines can cause a reaction. In addition, oil transferred from the plant to other objects (such as pet fur) can cause the rash if it comes into contact with the skin.

Poison Plants

Pacific Poison Oak – Toxicodendron diversilobum

Pacific Poison Oak

General:

Pacific poison-oak, a member of the sumac family, is a deciduous plant that grows throughout many parts of west coast. Urushiol, found on the stems, berries and leaves is the main component of the oily resin that causes rashes and blistering. Poison oak can survive under a wide range of temperatures, elevations, soil types, moisture conditions,

Description:

Western poison oak is variable in plant growth and leaf appearance. It can grow as a dense shrub, a tree with a 3” – 8” trunk or as a climbing vine.
When Pacific poison-oak grows as a shrub, it can reach up to 13 feet tall. When poison oak grows as a vine or tree, stems can reach up to 82 feet long. Twigs can be hairless to sparsely hairy and gray to reddish brown.

Leaves, generally resembling the leaves of a true oak, consist of three, and sometimes up to five leaflets but three leaflet leaves are most common. Leaf edges can be smooth, wavy, or have slightly rounded lobes. The upper leaf surface is hairless, or nearly so, and usually slightly glossy. The lower surface usually has sparse, short hairs. Leaves turn bright red in the autumn.

White flowers form in the spring in leaf axils, where the leaf meets or connects to the stalk, and white or tan berries usually form later in the summer

Without leaves, poison oak stems may sometimes be identified by occasional black marks where its milky sap may have oozed and dried.
Location: as the map indicates, western poison oak is found only on the Pacific Coast of the United States and of Canada. southern Canada to the Baja California peninsula.

Poison:

Urushiol binds to the skin on contact, where it causes severe itching that often develops into a red rash or flesh colored bumps and blistering. Symptoms generally appear 12 to 48 hours later. The rash can be treated with Calamine lotion or other over the counter remedies such as oatmeal baths and baking soda. In severe cases hospitalization may be required or if the plant has been ingested.

Urushiol oil can remain active for several years, so handling dead leaves or vines can cause a reaction. In addition, oil transferred from the plant to other objects (such as pet fur) can cause the rash if it comes into contact with the skin.
Severe respiratory irritation can be induced by breathing the smoke from burning plant material. Repeated exposure often results in increased sensitivity.