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Tony Bird
climber
Northridge, CA
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Topic Author's Reply - Jul 5, 2012 - 11:07am PT
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not sure what you mean by convergence, reilly, but i think skip is on the right track--there seems to be a mechanism involved, almost as if they're looking around and saying "i want to be like that". this little section of the backbone trail i was on last week inspired all this--examples of different leaf types within a few feet of each other, but apparently mimicking the other plants immediately next door. they didn't evolve that way, they grew that way from the last seed--or maybe even put out their most recent leaves to look like that.
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Reilly
Mountain climber
The Other Monrovia- CA
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they didn't evolve that way, they grew that way from the last seed.
Uh, with all due respect, I think you've been utilizing another type of leaf! ;-)
How could a plant grow a completely different type of leaf in one generation?
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justthemaid
climber
Jim Henson's Basement
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I've seen completely different leaf shapes sprouting out of different branches of (what seems to be) the same plant.
Now I'm curious. I'll have to do some poking around in Google for more info. I'm sure there are sub-species involved as well, but I'm not really that knowlegeable beyond my 9th-grade biology report on urishoil.
Side note: Sensitivity to urishoil is largely genetic and/or random. Some people get less sensitive with exposure and some people get more sensitive. It's a strange chemical and "conclusive" research seems to be all over the board . I was totally immune as a kid and now- with repeated exposure... can't be anywhere near it.
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Tony Bird
climber
Northridge, CA
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Topic Author's Reply - Jul 5, 2012 - 11:31am PT
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i don't think you're familiar enough with this plant, or plants in general, reilly--with due respect, of course, since you admit to being a plant noob. i've only gotten into it recently myself, with an interest in both foraging and gardening. most of us think of plant identification as fitting the patterns in the field to the pictures in a guidebook. watch an annual plant sometimes through the whole year, from cotyledon to death. you see lots of different leaf shapes.
i have an ebook by john kallas, who runs an interesting outfit in oregon called wild food adventures. he gives examples of the wild spinach plant (aka lamb's quarters, pigweed, goosefoot, etc) and its somewhat toxic look-alike, the hairy nightshade. the nightshade is adept at mimicking both the wild spinach and the also edible green amaranth with its leaf variations. wild spinach itself comes in many variations of leaf style. it's an easy forage in the alleys of the san fernando valley, but ya better know yer stuff 'cause it's not that far removed from a young locoweed plant in the same alleys, highly poisonous.
from kallas's edible wild plants: wild food from dirt to plate:
for our puposes, we will consider hairy nightshade poisonous. a few small leaves in a salad will not hurt you, but avoid eating this plant until we know more. the leaves of hairy nightshade look enough like wild spinach that you should learn to know this plant. hairy nightshade often intermixes with wild spinach and green amaranth. like a chameleon, its leaves can mimic both plants.
evolutionary selection? the subtlety of adaptation in a "subspecies"? i don't think so.
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Reilly
Mountain climber
The Other Monrovia- CA
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That's why I offered my humble comments with due respect. However, mimicry
and convergence I do know something about which is why I posed that question, respectfully. :-)
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Tony Bird
climber
Northridge, CA
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Topic Author's Reply - Jul 5, 2012 - 11:38am PT
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if you know about mimickry and convergence, you can't be a plant noob, and you'd better tell us more before skip goes out and starts rubbing leaves on herself.
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justthemaid
climber
Jim Henson's Basement
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Just a preliminary search on google. There are only 2 species (no sub-species)of poison oak listed on the botanical sites. There are 7 species of poison ivy.
"Left: Poison oak (Toxicodendron diversilobum) is described as a shrub, but it often grows like a climbing vine on the trunks of coast live oak (Quercus agrifolia) in Diego County. Right: Poison oak (A) and a related, look-alike shrub Rhus trilobata (B) that also belongs to the sumac family (Anacardiaceae). "
I couldn't find a single article on the mimicry PO seems to exhibit, although I did find one one on poison ivy doing the mimic-act. Strange... perhaps tony and I need to write one LOL.
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Reilly
Mountain climber
The Other Monrovia- CA
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If it is actually a case of mimicry then you have to explain the benefit to
the PO conveyed by its resemblance to the mimiced plant. Convergence is simply
that the PO and the similar plant arrived at the same form independently.
Birds and bats both have wings but they ain't related and it ain't mimicry.
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Brandon-
climber
The Granite State.
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I've read anecdotal evidence that eating cheese or milk from goats that forage on poison ivy (and I'd guess poison oak as well) will build an immunity to the rash.
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justthemaid
climber
Jim Henson's Basement
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I'm using the term "mimicry" sort of loosly since that is what it looks like to my eyes. I'm not even sure if plants can do that. I'm sure convergence plays into it, but doesn't really explain all of what Tony and I seem to have observed.
Using Reilly's example... it's the equivalent of the bat suddenly sprouting feathers because a pigeon lives on the ledge next door.
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labrat
Trad climber
Nevada City, CA
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Anyone trying these? I used them a bit 30 years ago but not lately. Below stolen from the website.
http://www.hylands.com/products/poisonivy.php
"Hyland's Poison Ivy / Oak Tablets are a traditional homeopathic formula for the relief of symptoms after contact with poison ivy or oak. Exposure to poison ivy / oak often results in skin breaks out with red, swollen, intensely itching, burning, watery blisters sometimes followed by oozing or crusting. Hyland's Poison Ivy / Oak is safe for adults and children and can be used in conjunction with other medications."
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justthemaid
climber
Jim Henson's Basement
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Yeah- I tried the Hylands tablets as well as a the Newton's homeopathics. They seemed to reduce the symptoms and duration a bit but by no means did they obliterate the PO rash. Definitely doesn't hurt to take them in conjunction with whatever other remedies you may be using but don't expect a magic cure.
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jstan
climber
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Once while bush whacking in shorts to reach a cliff, I discovered I was doing pull ups on PO. There followed two months of recurrent hell. Later recurrences were pain and inconvenience free because I had discovered hot showers produced the same feeling in infected areas as did scratching, but without scratching's damage. For me repeated exposure to bearably hot water has eliminated the need to scratch and complete relief from the problem, generally within two days and without a rash.
Many people have posted their favorite remedies here. Hot water is all I need. Also, I have never used a preliminary exposure to cold water.
Even were I an expert on the subject, internal application of urushiol is not something I would attempt. My past experience has been too unsettling. I assume you all have heard the urban myth about the fellow who was immune and rolled in burning PO. According to the myth the hospital could not save him.
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Tony Bird
climber
Northridge, CA
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Topic Author's Reply - Jul 5, 2012 - 05:10pm PT
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probably would hurt to reiterate what's been said about ingesting it.
i came across an account of it on the web by euell. he said he had heard the rumor for years, finally found a few people who could talk about doing it successfully, and decided to try it himself. he said his routine was to eat a single leaf at the beginning of the season every year. he also considered poison oak and poison ivy to be the same plant, so he may have been talking about poison ivy, which is similarly noxious because of the same chemistry, as far as i know.
what euell didn't mention in that interview was what you can expect if you try it--internal pains, reactions, perhaps some drastic overreaction, as certain people get to bee stings. this hasn't been researched, and it doesn't seem that the nannies in charge of universal safety are willing to tackle it, but i think it's certainly worth a closer look--by those with expertise in this area. gibbons, that santa cruz rancher, and now mention by timbrook all seem to indicate there's something to it.
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Tony Bird
climber
Northridge, CA
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Topic Author's Reply - Jul 5, 2012 - 08:43pm PT
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goodness--you go talk to the gal in the other room and find out all kindsa stuff.
urushiol--oil of urushi, the japanese word for the lacquer tree--and/or poison ivy.
the study cited above by banquo tells of resistance to urushiol irritation among japanese lacquer craftspeople, apparently developed through exposure at work. of course the fine lacquerware bowls do not irritate those who eat out of them, so something happens in the processing and drying of the lacquer. but mariko tells me it comes from the plant they call poison ivy.
i know from timbrook's book and other sources that the chumash and other indians in callifornia used poison oak for the dark dye used in baskets, i guess another example of resistance--or maybe rendering harmless during processing.
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Salamanizer
Trad climber
The land of Fruits & Nuts!
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I'm with Fattrad on this one.
Zanfel is where it's at for getting rid of the horrible rash.
Follow the directions to the T and 30 seconds later the itch is GONE... NEVER to return again.
Miracle stuff
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Tony Bird
climber
Northridge, CA
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Topic Author's Reply - Jul 6, 2012 - 08:58am PT
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haha, dingus--if you could only get away from all those trophy women, you'd start to notice stuff.
:-D
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Tony Bird
climber
Northridge, CA
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Topic Author's Reply - Jul 6, 2012 - 09:29am PT
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this study was conducted by me, the results duplicated by JTM, published in that impeccably peer-reviewed daily journal ST. not that i'm questioning your anecdotal information, dingus, but you should consider that our poison oak may be a tad cleverer down here.
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justthemaid
climber
Jim Henson's Basement
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Yes- our scientific conclusion is that poison oak is insidious, highly intelligent and deliberately mimics the plants around it for the sole purpose of luring us in to make us itchy. ;)
....
Alright.. I gave it some thought and I have to defect. In reality, it's probably more a result of water/light/nutrient availability as well as the convergence mentioned. With the sheer volume of PO around.. it does appear to deliberately mimic it's neighbors sometimes.
Some plants that seemingly have different leaf styles sprouting out of the same stands... the part of the plant growing under an oak tree gets more shade. Slower growth, less water and light seems to sometimes produce a darker-colored, smaller, more scalloped leaf that closely resembles the oak's leaves, while other parts that get more light and water have more tapered leaves with less scallops. (Just guessing here). Every little microcosm may effect the leaf growth.. even in close quarters.
PO just seems to have a rather astounding range of looks for what is basically just 2 species of plant. I also find it's ability to randomly decide to be a vine rather than a bush interesting. I wonder if a plant as tall as that 30-footer at Echo has feeder roots anchoring it in or if it is all just sprouting out of the base root ball. I'm not poking around it any time soon to find out.
PS @ Tony: Does this mean I'm going to get slipped a PO micky in my locally-foraged salad next time I have dinner at your place Tony?
PPS @ Dingus: Yes Dingus.. our poison oak is smarter than yours. So Cal PO works for Rocketdyne ya know.
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