Download Toxicodendron radicans

POISON IVY
When walking or working off the trails, one must be vigilant against various harmful
plants. One of the most harmful of the plants is Poison Ivy (Toxicodendron radicans [L.]
O. Kuntze). This plant is both fast-growing and long-lived.
Poison Ivy is a member of the Order Sapindales, the Family Anacardiaceae, and the
Subfamily Anacardioideae.
The generic name, Toxicodendron, is Greek for “poisonous tree or plant”. Toxico (or
toxikos) is “poison” or “poisonous” and dendron is “tree” or “plant”. The specific epithet,
radicans, is from the Latin word, radica, which is “roots” or “rooting”, referring to the
vines’ roots.
Previous scientific synonyms for this species were Rhus radicans L. and Rhus
toxicodendron L. The generic name, Rhus, is a Greek and Latin name for “sumac”.
Poison Ivy was first named by Captain John Smith, founder of the Jamestown Colony,
in 1609. Other common names for this plant are Climath, Climbing Ivy, Climbing
Sumac, Common Poison Ivy, Cowitch, Eastern Poison Ivy, Gift Sumac, Gowitch,
Markwood, Mercury, Picry, Poison Creep, Poison Creeper, Poison Mercury, Poison
Vine, Poisonwood, Poor Man’s Liquid Amber, and Three-leaved Ivy.
DESCRIPTION OF POISON IVY
Perennial
Form: Poison Ivy can take upon different forms. It can be an erect upright shrub, a
sprawling or trailing vine, or a thick climbing vine. These vines do not twine around
other objects. The vines and the shrubs make ideal Bird (Class Aves) nesting habitats.
Height: Its height is variable. The shrub may be about 2-10 feet, and the climbing vine
may be over 75 feet.
Stem: Its climbing vine stems are woody, hairy, strong, and flexible. They have no thorns
or spines. The resin canals are arranged in circle like numbers on a clock.
Wood: Its wood is soft, porous, and has raised pores. Its sapwood is wide and lightcolored.
Twigs: Its twigs are brown or tan. They are softly hairy their 1st year and smooth their 2nd
year. Its leaf scars are U- or V-shaped and have 6 bundle scars. Eastern Cottontail
Rabbits (Sylvilagus floridanus J.A. Allen) eat these twigs.
Buds: Its terminal buds are dark tan, hairy, slender, pinched at the base, and slightly
curved at the tip. Its lateral buds are smaller, hairy, and appressed.
Leaves: Its leaves are deciduous, alternate, and pinnately compound with 3 leaflets. They
are located near the tip of the branch. The 3 leaflets are variable. Each leaflet is oval,
ovate, or rhombic; has a rounded or a wedged base; and has a pointed tip. They may be
glossy, dull, or hairy. They may also be thin, stiff, and leathery. The side veins are
alternate. The margins are entire, wavy, toothed, or lobed. The leaf petiole is about 2½-6
inches long, slender or thick, glossy to hairy, and has a thick base.
The middle or end leaflet is about 1¼-8 inches long, about ½-5 inches wide, and has a
½-1 ¾ inch leaf stalk. The 2 smaller side leaflets are about 1¼-6 inches long, about ½-4
inches wide, have a1/8 inch long leaf stalk, and have unequal sides.
These leaves turn red, orange, or yellow in the fall. White-tailed Deer (Odocoileus
virginianus Zimmermann) and livestock may eat these leaves without suffering any ill
effects.
Flower: Its flowers are alternately arranged in loose, open, axillary, slender, and irregular
panicled spike clusters that are about 1-4 inches long. Each flower is white, yellow, or
green; radially symmetrical; and about1/8-¼ inch wide. It has a calyx with 5-lobes; a
corolla with 5 smooth, triangular and recurved petals; 5 separate stamens with white
filaments and yellow-brown anthers and that extend beyond the flower; and 1 pistil with a
3-parted stigma, a stout style, and a single celled ovary. These flowers are either
unisexual or bisexual. Bees (Superfamily Apoidea) and Flies (Order Diptera) pollinate
these flowers. Flowering season is May to July.
Fruit: Its fruits are arranged in clusters. Each fruit is a dry, globose, and waxy drupe or
berry. The fruit is white, tan, gray, yellowish, or cream. It is about ¼ inch in diameter. Its
outer coat is papery with shallow, longitudinal grooves and its inner coat is fibrous.
Yellow-rumped Warblers (Setophaga coronata L.), Northern Bobwhite Quails (Colinus
virginianus L.), American Crows (Corvus brachyrhynchos Brehm), Wild Turkeys
(Meleagris gallopavo L.), Cedar Waxwings (Bombycilla cedrorum Vieillot), American
Robins (Turdus migratorius L.), Dark-eyed Juncos (Junco hyemalis L.), Woodpeckers
(Family Picidae), and over 75 other bird species eat these fruits. Fruiting season is
August to November but may remain upon the plant throughout the winter.
Seed: Its seeds are a single, hard, and striped stone. The seeds pass intact through a bird’s
digestive system to spread this plant.
Roots: Its root system is extensive. It has a woody taproot. Its rhizomes may run under
ground and send up leafy shoots at their nodes to form clonal colonies.
Climbing vines have aerial rootlets. These roots are bright red and fuzzy when young
but later become brown or grayish black. The rootlet hairs secrete a powerful adhesive
that attaches them to the tree. These roots are not parasitic to the tree.
Bark: Its young bark is red-brown and smooth. Its mature bark is gray-brown, thin, and
slightly scaly or flaky.
Habitat: Its habitats consist of open woods, thickets, woods’ edges, fields, pastures,
fencerows, roadsides, railroads, and disturbed waste areas. It is moderately shade tolerant
but grows best in open sunlight.
This plant often appears near settled areas. It is more common now than before the
European settlers arrived.
Range: Its range covers most of the eastern U.S. and southeastern Canada. It also
includes Mexico, Central America, West Indies, Bermuda, and the Bahamas.
It is also native to parts of Japan, China, Korea, and Russia. It may have migrated to
North America via the Bering Land Bridge.
In 1632, it was introduced to England. It has since been introduced to the rest of
Europe and to other countries.
Urushiol:
Urushiol (or toxicodendrol) is a yellowish, toxic, irritating, and heavy non-volatile oily
oleoresin alkaloid. It is found in nearly all parts of the plant. It is from the Japanese word,
urushi, which is “lacquer”. It is not found in the pollen or in leaves that have fallen in the
fall after the urushiol has returned to the stem. It is produced in the plant’s resin ducts and
is produced year-round. It is an allergen and causes Rhus dermatitis in most people.
Urushiol is a persistent chemical. It can still be found upon the dead and dry plant. It
can remain active for up to 100 years. It turns brown then black upon exposure to the air.
If it comes in contact with clothing, tools, or animal fur, the urushiol persists upon them.
It takes only 1 nanogram (1 billionth of a gram) to cause this allergic reaction. A single
pinhead can have enough urushiol to affect 500 people.
Symptoms:
To get the affliction, one must come in contact with the plant. It may even take
repeated contact. One cannot get it from looking at it. However, the urushiol can get in
the smoke of the burning plant and can affect people.
Symptoms of the affliction include inflammation, irritation, itching, redness, and
swelling. These symptoms may appear from a few hours to several days after contact.
This varies with the degree of contact with the plant and with the individual’s
susceptibility.
Almost all parts of the body are susceptible. However, the hand palms, the feet soles,
and the scalp all have tougher skins and are less susceptible.
About 70-85% of humans are susceptible to Poison Ivy. A person’s sensitivity can vary
with age. A younger person is usually more sensitive than an older person.
Later symptoms may consist of blistering. These blisters may break open and exude
fluids. This fluid consists of clear blood plasma that does not have urushiol. These fluids
later dry up and form scabs and crusts. These symptoms may last about 2-3 weeks.
A few people may experience flu-like symptoms, such as fever and headaches.
Scratching may spread the rash if oil is present upon the skin. Scratching may also lead
to infection.
Treatment:
If one does come into contact, that person should immediately wash the area with cold
water, with rubbing alcohol, or with vinegar. Warm water opens the skin pores to allow
the oils to enter the skin. Detergents or alkaline soap should also be used. Oil-based soaps
may spread the urushiol. The washing should be done within 5-10 minutes, before the oil
penetrates the outer skin and bonds with the proteins and the lipids of the inner skin.
Bleach, ammonia, gasoline, kerosene, turpentine, or lacquer thinner are harmful to the
skin and should not be used. Although the oil is water insoluble, the water should dilute
and oxidate the oil and make it less potent.
If one gets the symptoms, creams and ointments that contain corticosteroids and
antihistamines can treat the rash and the itching. Some of these require prescriptions.
Calamine lotion should dry the rash. More serious cases should seek medical attention.
A few native plants have some medicinal properties that may relieve some of the
discomfort. Jewelweed (Genus Impatiens), Common Witch Hazel (Hamamelis virginiana
L.), and Solomon’s Seal (Polygonatum biflorum Elliott) washes are effective. Poultices of
the Ragweeds (Genus Ambrosia) or of the non-poisonous Sumacs (Genus Rhus) are also
effective against this plant’s discomfort.
Contaminated clothing should be washed separately to avoid contaminating other
clothes. Use hot water and plenty of detergent. Repeated washing may be better.
Cultural History:
Poison Ivy has played a role in our nation’s cultural history. Bob Kane’s DC comic
book character, Batman, had a villainess named Poison Ivy (Dr. Pamela Lillian Isley).
Many adages have been written or said about Poison Ivy and its various plant parts.
Some of these adages are “leaflets three, let it be”, “leaflets three, turn and flee”, “leaflets
three, quickly flee’, “alternate leaf, possible grief”, “fruit white, a warning sight”, “berries
white, take flight”, “hairy vine, a danger sign”, “hairy vine, no friend of mine”, “climbing
vine, not so fine”, and “only a dope swings from a hairy rope”.
Future of Poison Ivy:
While our planet is experiencing global warming, it is having an effect upon the Poison
Ivy. The increased levels of carbon dioxide in the atmosphere are encouraging the growth
of this plant. It is also producing more urushiol in both volume and potency. Future
generations may suffer even more severe allergic reactions.
REFERENCES
THE POISON IVY, OAK, AND SUMAC BOOK
By Thomas E. Anderson
THE POISON OAK AND POISON IVY SURVIVAL GUIDE
By Sandra J. Baker
FALL COLOR AND WOODLAND HARVESTS
By C. Ritchie Bell and Anne H. Lindsey
NATIONAL WILDLIFE FEDERATION FIELD GUIDE TO WILDFLOWERS OF NORTH AMERICA
By David Brandenburg
MEDICINAL AND OTHER USES OF NORTH AMERICAN PLANTS
By Charlotte Erichsen-Brown
POISON IVY, pets, AND PEOPLE
By Heidi Ratner-Connolly and Randy Connolly
MISSOURI WILDFLOWERS
By Edgar Denison
THE BOOK OF FOREST AND THICKET
By John Eastman and Amelia Hansen
POISON IVY, POISON OAK, POISON SUMAC, AND THEIR RELATIVES
By Edward Frankel, Ph. D.
NATURE’S REVENGE/OUTWITTING POISON IVY
By Susan Carol Hauser
WILDFLOWERS OF OHIO
By Robert L. Henn
POCKET GUIDE TO THE WILDFLOWERS OF NORTH AMERICA
By Catherine Herbert Howell
NATIONAL WILDLIFE FEDERATION FIELD GUIDE TO TREES OF NORTH AMERICA
By Bruce Kershner, Daniel Mathews, Gil Nelson, and Richard Spellenberg
POISONOUS PLANTS OF THE UNITED STATES
By Walter Conrad Muenscher
EDIBLE AND MEDICINAL PLANTS OF THE GREAT LAKES REGION
By Thomas A. Naegele, D.O.
NEWCOMB’S WILDFLOWER GUIDE
By Lawrence Newcomb and Gordon Morrison
TREES AND SHRUBS
By George A. Petrides
SEASON OF PROMISE
By June Carver Roberts
ALL ABOUT WEEDS
By Edwin Rollin Spencer
POISONOUS PLANTS OF THE CENTRAL UNITED STATES
By Homer A. Stephens
WICKED PLANTS
By Amy Stewart
THE NATURAL HISTORY OF WILD SHRUBS AND VINES
By Donald W. Stokes
THE USES OF WILD PLANTS
By Frank Tozer
COMMON POISONOUS PLANTS AND MUSHROOMS OF NORTH AMERICA
By Nancy J. Turner and Adam F. Szczawinski
SHRUBS AND WOODY VINES OF INDIANA AND THE MIDWEST
By Sally S. Weeks and Harmon P. Weeks
en.wikipedia.org/wiki/Toxicodendron-radicans
www.illinoiswildflowers.info/trees/plants/poison-ivy.htm
www.poison-ivy.org
poisonivy.aesir.com/view