Poisonous Plants - Tulsa Master Gardeners

Poisonous Plants
Two Categories of Poisonous Plants
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Mechanical Damage
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Stinging Nettle
Cacti
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Lodge in mouths of
livestock
Scouring Rushes
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Cause digestive upset in
cattle
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Chemical Damage
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Poison Ivy
Poison Oak
Poison Sumac
Yew, Hemlock, Wild Cherry
and other ornamental plants
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Poisonous to children, adults and
livestock
Poison Ivy & Poison Oak
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All parts are poisonous
Toxin is active year round
Toxic oil, urushiol, can get on skin, clothes, pet
fur, shoes
Oil can remain active on clothing up to one
year.
We do not have poison Sumac in Oklahoma
Basic Symptoms
Rash & Itch: 24-48 hrs
 Blisters
 Reaction to oil
Prevention after exposure
 Wash with cold water 1
hr or less
 Do not shower with
hot/warm water

Do Not Rub Eyes or Face
Seek Prompt Treatment
Reactions vary
 Over counter treatments
 Immunity
Best prevention
 Avoid plant
 Lotions –Tech Nu
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Air near plant not
contagious
When Is It An Emergency?
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If rash develops within 4 hours instead of 24 to
48 hours after exposure
If eyes swell shut
If breathed smoke from burning poison ivy
Basic I.D. of Poison Ivy
Poison Ivy (Toxicodendron radicans)
– many species; T. radicans
most common
 Three green leaflets with a few
teeth
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Red petioles
Dull green appearance, but
can be shiny, too.
Small Woodland Plant
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May grow among other
plants
Three leaves
Red petioles
Poison Ivy vines are the
same plant
Fruits: small, waxy, cream
colored that later turn white
Poison Ivy
Where does it grow?
Grows almost everywhere
On the ground
 Climbing
 Rural Road Sides
 Utility Poles
 New Suburban Areas
 Abandoned Areas

Where does it grow?
Climbing poison ivy will climb
anything, and can be mistaken for the
leaves of a host tree.
Shrub Form of Poison Ivy

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Often called poison oak – Incorrect
Grows where no tree is available for plant to
climb
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Grows as single stem at 45 degree angle
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Has white stems with large lenticels
Winter I.D. of Poison Ivy
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Prominent aerial roots
White stems with large
lenticels
White berries
How to Recognize
Poison Ivy
Winter
Ground vines in winter are
almost impossible to
recognize.
(This poison ivy patch was identified
only from visits during the summer)
Poison Ivy Look-alikes
Poison Oak: Eastern poison oak
(Toxicodendron quercifolium)
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Leaves with oak leaf shape
Shrubby non-climbing habit,
lack of aerial roots
Occurs across the body of the
state, with greatest abundance in
the eastern half
Poison Ivy Look-alikes
What is NOT poison ivy
Virginia Creeper is commonly
mistaken for poison ivy.
Creeper has leaves in groups of 5,
poison ivy has leaves in groups of
3.
Both plants often grow side by
side.
Poison Ivy Look-alikes
Virginia Creeper:
 5 Leaves
 No Rash
 Induced by Exposure.
 Can grow entwined with
Poison Ivy
Controlling Poison Ivy
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Do NOT Burn! Smoke carries oil droplets
Spot treatment - Glyphosate (RoundUp, etc. in late Spring
through mid-Summer)
Triclopyr (Remedy - mid-summer) – control in large
established areas
Cut vines six inches above ground, treat fresh cut with
Glyphosate.
Do NOT tear vines out, they’ll just re-grow.
Is there poison ivy here, and if so
where, exactly?
Jewelweed
Only these
are
Poison ivy
Leaves of Three….Leave it Be