Poison-oak: getting to know your enemy
Leaves of three – let it be.
Leaves of three – the mantra. Just what does that mean? Our “off the trail’ scramble down to Sespe Creek ran us into poison oak that was fairly recognizable because of the time of year – late summer. It’s not always that discernible when mixed with other plants and earlier in the year. It is nevertheless just as potent. Sometimes I can’t always tell it from other plants – especially the ‘leaves of three’ part. I did some research and found good examples of poison oak in different settings and colors. I hope you find this as informative as I have. Color printouts now go in my backpack.
from Wikipedia
Toxicodendron diversilobum (syn. Rhus diversiloba; Western Poison-oak or Pacific Poison-oak) is a plant best known for its ability to cause allergic rashes after contact. Western Poison-oak is found only on the Pacific Coast of the United States and of Canada. It is extremely common in that region, where it is the predominant species of the genus; the closely related Atlantic Poison-oak (T. pubescens) occurs on the Atlantic Coast. The hyphenated form “Poison-oak” is used, rather than “Poison Oak” to clearly indicate that it is not a variety of oak, just as “Poison-ivy” is not a variety of ivy.
Western Poison-oak is extremely variable in growth habit and leaf appearance. It grows as a dense shrub in open sunlight, or as a climbing vine in shaded areas. Like Poison ivy, it reproduces by creeping rootstocks or by seeds. The leaves are divided into three leaflets, 3.5 to 10 centimeters long, with scalloped, toothed, or lobed edges– generally resembling the leaves of a true oak, though the Western Poison-oak leaves will tend to be more glossy. Leaves are typically bronze when first unfolding, bright green in the spring, yellow-green to reddish in the summer, and bright red or pink in the fall. White flowers form in the spring and, if fertilized, develop into greenish– white or tan berries. Toxicodendron diversilobum is winter deciduous, so that after cold weather sets in the stems are leafless and bear only the occasional cluster of berries. Without leaves, poison oak stems may sometimes be identified by occasional black marks where sap may have oozed and dried.
Botanist John Howell observed that Toxicodendron diversilobum’s toxicity obscures its merits. “In spring the ivory flowers bloom on the sunny hill or in sheltered glade, in summer its fine green leaves contrast refreshingly with dried and tawny grassland, in autumn its colors flame more brilliantly than in any other native, but one great fault, its poisonous juice, nullifies its every other virtue and renders this beautiful shrub the most disparaged of all within our region.”
on poison-oak by palomar.edu
Has anyone got any additional information out there on poison-oak? Any home remedies that you’ve tried and that works? How about any strange poison-oak experiences you’ve had?
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I am very allergic to poison oak and this was a very helpful post. There are many new over the counter remedies available. Time is of the essence. You can buy remedies to wash off the oils.