Eating poison ivy – does it make you immune?


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Poison Ivy
Eastern Poison Ivy (By Sam Fraser-Smith from Brisbane, Australia/ Wikimedia Commons)

Many of us in the U.S. have had a traumatic run in with poison ivy or Poison Oak(on the west coast) at some point or another. I am only mildly allergic to poison Ivy but that doesn’t mean I was immune to it’s reign of terror when I unknowingly brought it home to my highly allergic wife on my jacket. Developing an immunity to poison ivy would be life-changing for some and at least very helpful for the majority of us. Poison Ivy(Toxicodendron radicans), Poison Oak(Toxicodendron diversilobum) and Poison Sumac(Toxicodendron vernix) are all species in the genus Toxicodendron and the information in this article generally applies to all these plant.

There are many anecdotal reports of people eating poison ivy and developing immunity. I went in search of as much information on the topic as possible. I wanted to know how poison ivy affects us and what is the best way, if any to develop a better immunity to it’s affects on the body. This article contains a summary of what I found.

How Many People Are Allergic to Poison Ivy and Poison Oak
According to americanskin.org roughly 85% of people are allergic to urushiol, the irritating compound in poison ivy and 10%-15% of people are highly allergic.   When it comes to an individual’s reaction it’s somewhat more complicated because people can develop sensitivity over time and some people even decrease sensitivity over time. So the way that you react to poison ivy now may not be the same in a few years or decades. From my personal experience I have noticed that especially for people who have never or rarely come into contact with poison ivy, it sometimes takes a few interactions before they react, and that first reaction could be very bad.  The moral of the story is if you have touched poison ivy a few times and seem to be immune don’t take a dare to roll it in, or rub it all over your face, you might regret it.

How Poison Ivy and Poison Oak Affect the Body
Believe it or not poison ivy does not actually directly cause the rash that you see when you come into contact with it. That rash is caused by an allergic reaction to the urushiol oil contained in the plant. An allergic reaction starts when your body identifies a foreign invader, in this case urushiol. Then our bodies produce antibodies which produce histamine. Histamine is helpful against invaders of our body because it expands blood vessels in the area which allows our immune system to better access and defeat the foreign invaders. The problem occurs when too much histamine is produced, this is an allergic reaction and this is the case with poison ivy.  Too much histamine can cause rash and swelling and in some cases actually does damage to the area instead of just fighting off the invaders. So what really takes place during an allergic poison ivy reaction is that our body over-reacts and ends up damaging itself in the process.  Poison ivy has evolved a way to trick the immune systems of 85% of people into damaging themselves with their own defense mechanisms. In reality our bodies do not need to react to urushiol oil and this non-reaction is what happens in the bodies of the lucky few who do not have noticeable reactions to poison ivy, poison oak, or poison sumac.

Is It Possible to Develop an Immunity to Poison Ivy?
The definition of the word “immunity” is “the ability of an organism to resist a particular infection or toxin by the action of specific antibodies or sensitized white blood cells”. Since poison ivy is not an infection or toxin you can’t become immune to it, but this word has still become a generally acceptable term to describe becoming non-sensitive to poison ivy, so I’ll continue to use it throughout this article. In regards to the coveted poison ivy immunity there is not a lot of evidence on the topic but this artice from WebMD says that it might be possible to develop an immunity through a series of small exposures over time. Giving a patient small exposures of an allergen over time is a common way to train the body to not over-react when facing those allergens, this method is sometimes called immunotherapy or sensitivity treatment.  keep in mind this process is done to very specific guidelines by a doctor.

Is Eating Poison Ivy Safe?
Your instincts are correct, eating poison ivy is very dangerous. I have heard that if you eat poison ivy your mucous protects the skin inside your mouth and throat  so that you don’t have a reaction.  Although there potentially might be some truth to this, there are so many things that could go wrong.  Many things like alcohol,smoke or certain foods can decrease mouth mucous, so the protection would be gone, a leaf could get stuck in the throat and work its way through the mucous. or you might be extra sensitive and your mucous isn’t enough to protect you.

My Experiment Eating Poison Ivy
I know I just spent the last paragraph telling you how stupid it is to eat poison ivy, but there was a time that i did eat small amounts of poison ivy every few months over the course of a few years.  I wrapped the poison ivy in Violet or Yard Plantain leaves so that it wouldn’t come in contact with my throat. I didn’t have any bad reactions in my throat, but I also didn’t become immune, I have had nearly the exact same reaction since I was a kid, this period of time eating leaves, didn’t help. But there are examples of people who have eaten poison ivy and had the expected bad reaction, so I’m still urging readers not to be one of those people.

Conclusion
The conclusion is that This topic is not simple. There are stories of people decreasing and increasing sensitivity over the course of multiple exposures at different points in their lives. How sensitive an individual is seems to be due to multiple factors such as genetics, exposures, and environment. The facts we have are that there is no solid proof yet that eating poison ivy is beneficial in any way and we do have solid proof that eating poison ivy can be very dangerous. So clearly the best thing to do is not to attempt to eat poison ivy.

If You Must
If you’ve still got your heart set on eating poison ivy you can try a homeopathic remedy.Two products available are Natrabio Poison Oak/Poison Ivy and Boericke & Tafel – Oral Ivy. These products are probably diluted to the point that they don’t even contain any urushiol anymore, but hey they might be worth a try. Please leave any comment with your experiences eating poison ivy or homeopathic remedy or being smart and deciding not to eat poison ivy.


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Dogwood Tree – Beautiful Flowers, Unique Fruits


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Dogwood Tree

Dogwood Tree
Flowering Dogwood (Photo By: Line1 / Wikimedia Commons)

Dogwood trees are trees in the Genus: Cornus.  This Genus consists of 30-60 mostly woody plants some of which grow into small trees.  The Dogwood tree is an extremely common ornamental plant, dogwood trees offer beautiful flowers and unique fruits. Dogwood trees do not get very tall and are ideal for landscape plantings where small trees are desired. Some  are native to the U.S. and some are not, such as the very popular Kousa Dogwood which is native to Asia. Dogwoods all have berries but not all are edible. Dogwood fruit comes in many shapes, sizes and colors. This article will discuss a few of the most common dogwood tree species and how to identify them by flowers or fruits and weather the fruits of that species are edible.

Flowering Dogwood – Not Edible

Flowering Dogwood Berries
Flowering Dogwood Berries

Flowering Dogwood(Cornus florida) is one of the two most common ornamental species of dogwood tree, the other is Kousa Dogwood. This species is native to the eastern United States, It grows well in woodlands as well as landscapes. Flowering dogwoods prefer part shade and are perfectly adjusted to the acidic soil of the northeast.

These dogwood berries are not edible.

Some reports say they are poisonous. The berries are very astringent and bitter.  The red berries grow in clusters and mature into the fall.

Identification – Flowering dogwood leaf / fruit clusters

All Dogwood trees have similar shaped leaves. these are simple leaves with an ovate shape and visible leave veins. Ovate leaf shape is one of the most common leaf shapes so dogwood leaves are not easily identified by their leaves. Flowering Dogwood can be identified by their fruit clusters. These are red fruit clusters with elongated fruits. as mentioned above the fruit is not edible.

White Dogwood and Pink Dogwood

Pink Dogwood Flower
Pink Dogwood (Photo By: Reggaeman / Wikimedia Commons)

Flowering Dogwood(Cornus florida) has very showy flowers in early spring. This species is cultivated very frequently and different varieties have been developed.

Dogwood flower – Or is it?

Technically the showy part of the dogwood flower is not a flower petal but a modified leaf called a bract.  The flowers of Cornus florida are usually white but pink flowered varieties have been developed.  Both pink and white flowered dogwood are very common.

 

Kousa Dogwood – Edible Fruit

Kousa dogwood(Cornus kousa) is another very popular ornamental dogwood. This species is native to Asia, there are a number of varieties with slightly different flower and fruit characteristics.  Kousa dogwood are planted because of their small size and relatively good pest resistance. They get flowers in the spring and fruits in late summer and early fall.

Kousa Dogwood Berries
Kousa Dogwood Fruit

This dogwood fruit is edible

The fruits of this species are edible and one of tastiest and prolific wild edibles that can be found in the landscape. Although not truly a “wild” edible because kousa dogwood does not naturalize frequently in most areas.  Part of the trick to harvesting kousa dogwood berries is choosing berries at the right stage. Read THIS article on kousa dogwood if you’re interested in more information on how to know when kousa dogwood berries are ready to eat.

Kousa Dogwood can be identified by 2 primary factors. The bark and the fruits.  As kousa dogwood gets older the lower bark peels and creates a unique pattern similar to sycamore tree bark.  The kousa dogwood berries are unique in size and shape.  They are red berries formed into an approx, 1″ diameter fruit, this is technically an aggregate fruit but looks like a single large berry. The outer skin on the berry somewhat resembles lychee fruit.

Cornelian Cherry Dogwood – Edible Fruit

Cornelian cherry dogwood(Cornus mas) is another dogwood tree that is commonly sold as a landscape tree.  This tree is not used nearly as often as the other species mentioned above, but it still has some interesting potential in the landscape. This tree is native to Eurasia but grows very well in the eastern U.S. One of the most fascinating features of this plant is it’s early flowering period. This plant flowers very early, sometimes before forsythia, it also has small yellow flowers not unlike forsythia.

Cornelian Cherry Dogwood Berries
Cornelian Cherry Dogwood Berries (Photo by: Art Anderson / Wikimedia Commons)

The fruits of this species are edible. They are a single dark red smooth berry when ripe in summer. There is one large seed in the middle of each berry but you still get a significant amount from each fruit . They have a good taste but are very sour.  I happen love sour fruits so they are one of my favorites.  Cornelian cherry dogwood trees frequently get covered in berries so  it is possible to use them in pies and jams.

Even though the leaves and bark are very similar, distinguishing this tree from flowering dogwood is easy.  This tree has a completely different flower and fruit schedule then the flowering dogwood. Cornelian cherry dogwood flowers and fruits much earlier. So at any point throughout the year except for winter you should be able to see flowers or fruits or expect to see them depending on which tree your looking at.  Since the berries and leaves on this tree are not distinctive enough compared to other plants in the landscape it’s recommended that if you believe you are looking at a cornelian cherry dogwood then you should compare that plant directly to an identification guide.

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FACW – Discover This Amazing Natural Resource


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Swamp Milkweed
Swamp Milkweed Pod

FACW plants are plants that can to grow in wetlands but may also be found outside of wetlands.  These are versatile plants that can grow in many conditions.  This includes trees such as red maple(Acer rubrum), Serviceberry (Amelanchier), river birch (Betula nigra), certain types of dogwoods (Cornus) and a vast assortment of other trees, shrubs and herbaceous plants. Versatile plants such as these are valuable natural resources that may be able to thrive despite changing weather patterns.

Wetland Indicator Status

FACW is a category of the wetland indicator status. The wetland indicator status of a plant is a system of categorizing plants based on likelihood of being found in a wetland environment. A list of approximately 7000 plants was compiled in 1988 by the U.S. fish and wildlife service in conjunction with a federal inter-agency review panel. This list had the lengthy name of the national list of plant species that occur in wetlands.  There are 5 categories of estimated probability of a plant species naturally growing in a wetland environment:

  • OBL– Obligate wetland  (estimated probability > 99%)
  • FACW– Facultative wetland  (estimated probability 67% – 99%)
  • FAC– Facultative(estimated probability 34% – 66%)
  • FACU– Facultative upland  (estimated probability probability 1% – 33%).
  • UPL– Obligate upland  (estimated probability < 1%)

FACW

FACW plants
FACW

Facultative wetland plants are plants such as pennsylvania bittercress that are very likely to be found in a wetland but occasionally grow in non-wetland areas. Some plants are considered FACW in some regions but considered FAC in other regions.  This usually depends on weather patterns and climate.

Recent Changes

There have been subsequent updates to the list in 1996 and 1998. In 2012 the national wetland plant list replaced the national list of plant species that occur in wetlands. The new list can be search here at the department of agriculture website. This new list is a very useful list for finding out where specific plants grow, this can be used for finding specific species or for narrowing down species for identification.

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