Transcript stinging nettles

Stinging, Itching, Burning,
WICKED Plants
Patti Anderson, Botanist
Division of Plant Industry
Which plants are wicked?
Toxicodendron radicans
Leaflets 3
Let it be!
Leaflets 3
Let it be!
The Familiar Trio of Itching
• Poison Ivy
• Poison Oak
• Poison Sumac
… but they are not alone!
Watch out for the Anacardiaceae family
Toxicodendron radicans
POISON IVY
• clusters of three leaflets
• alternate leaves
• no thorns or spines
The appearance of poison ivy can vary greatly between
environments and even individuals within one area.
Non-itching Poison Ivy Look-alikes
• Virgin's Bower (Clematis virginiana)
• Box-elder (Acer negundo)
– saplings
• Virginia Creeper (Parthenocissus quinquefolia)
– early leaves
Toxicodendron pubescens
POISON OAK
• upright shrub
• to 1 m (3 ft) tall
• alternate leaves
• three leaflets
• leaflets usually hairy, variable in size and
shape, but often resembling white oak leaves
Toxicodendron vernix
POISON SUMAC
•
•
•
•
•
shrub or small tree
up to 7 m (23 ft) tall
alternate leaves
7-15 leaflets
white fruits
Non-itching Poison Sumac Look-alike
Rhus copallinum – winged sumac
But wait
What other plants are in this wicked family?
• trees with simple leaves
Anacardium occidentale (cashew )
Patches of black dried resin appear on
many of these species
Poisonwood
native to South Florida
• tree with 3-7 leaflets
Metopium toxiferum
Poisonwood
Produces an intense poison-ivy-like dermatitis
And see what a mango can do
Urushiols
Urushiols are phenolic compounds found in the
family Anacardiaceae.
These compounds are soluble in oils and alcohols
and cause a blistering rash on sensitive individuals.
Urushiols
• colorless or pale yellow oil
• in all parts of the plant, including roots,
stems, and leaves
After 15 – 30 minutes, the urushiol bonds
with oils on the skin and can no longer be
washed off.
Prevention
• Learn to identify and avoid these plants
• Wear protective clothing
• Wash all tools, clothes and anything else
touched by these plants
• If you’re allergic to mangos, ask
someone else to peel them
Prevention
Try products that can help keep the
itching oil from getting into your skin.
For example, “Ivy Block” is a lotion that forms a
clay-like barrier on the skin.
Treatment
• Washing with cool water and soap or rubbing
alcohol within 15 minutes of initial exposure
may help to prevent a rash
• After the rash has developed, the only
treatment is to relieve symptoms.
Treatment
• If the rash is widespread or results in a large
number of blisters, see your doctor.
• Bathing in tepid water with Aveeno® oatmeal
may soothe itchy skin.
• You could need an ocean of
Calamine Lotion.
Treatment
If all else fails, think positive—
Most rashes clear up
within 1 – 3 weeks.
And remember what your
mamma said,
“Don’t scratch!!!”
Wicked Stinging Plants
Several species are known as stinging
nettles in Florida.
Two are common in North Florida.
Stinging Nettle or Tread Softly
Cnidoscolus stimulosus
• showy flowers
• large, lobed leaves
• alternate leaves
• milky sap
• stinging hairs
Stinging Nettle
Urtica dioica is native
to North America, but
not Florida.
Not often seen here,
but used in herbal teas.
Urtica dioica
Photo from Wikimedia
Stinging Nettle or Fireweed
Urtica chamaedryoides
• opposite leaves
• leaf margins with teeth
• tiny flower clusters
• STINGING HAIRS
Urtica chamaedryoides
Photo by Jeffrey W. Lotz
Photo from Wikimedia
Stinging Nettle
Why are the Urtica species so wicked?
• stinging hairs - like glass rods with a bulb
at the base
• break off on contact
• hold irritating chemicals
• similar to insect venom
Photo from Wikimedia
• NOT life threatening – you’ll just wish . . .
Burning Plants
Dieffenbachia species – dumb cane
Beautiful foliage,
but don’t taste it!
Burning Plants
Dieffenbachia species
• large, clasping leaves
• fleshy green stem
• flowers a spathe and spadix
• all parts contain milky latex
and calcium oxalate
crystals
Dumb cane crystals
• Biting, chewing or tasting causes
burning, swelling and irritation
• Swelling of the tongue and throat
may make speech impossible
• Also good for making
arrow poison
WICKED WICKED PLANTS!!!
Some plants are irritating and invasive!
But so pretty….
WICKED!!!
Schinus terebinthifolia
Brazilian pepper
Poison ivy relative
(dermatitis possible)
And
A noxious weed
Schinus terebinthifolia
• alternate leaves
• glossy green with prominent white veins
• 3-11 leaflets
• irritating sap
• extremely invasive
• treatment
as in poison ivy
WICKED!!!
Some plants are weapons
grade toxic and invasive!
But so pretty….
Ricinus
communis
Castor bean
Ricinus communis
Castor bean
• shrub or small tree (10m/33ft)
• large, palmate-lobed leaves
with long petioles
• spiny fruit
• toxic seeds (ricin)
• invasive
•treatment
- see a doctor fast!
References
Guide to the poisonous and irritant plants of Florida
http://ufdc.ufl.edu/UF00000155/0001/1j
Any Questions
about your friendly
Stinging, Itching, Burning,
WICKED Plants