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Poison Ivy Thriving

10-24-13  poison ivy2  029Poison Ivy is in the Anacardiaceae family, which also includes cashews, mangos and sumacs. The sap of the stems, roots, fruit and leaves of many species in this family contains urushiol oil, which is what causes the allergic rash in 80% of humans that come in contact with these species. Poison Ivy is very sensitive to carbon dioxide, and even slightly elevated levels of CO2 have proven to increase its growth. In the past 50 or 60 years, during which time the amount of carbon dioxide in the atmosphere has increased by roughly 22%, Poison Ivy’s growth rate has doubled. The amount of urushiol oil has not only increased, but it is also more potent…leaves of three, let them be.

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6 responses

  1. As a landscaper, my hands always reaching to pull weeds, my eyes are always on the look out for where my hands are going, to stop before touching and getting my gloves on.
    Looking forward to hearing and seeing you this Saturday in NH

    October 24, 2013 at 1:12 pm

  2. Cecelia Blair

    Poison Ivy likes road salt too very much, which is why it is so often found next to roads. This is trouble when there is no sidewalk or good space to get away from traffic, and you step into the shrubbery with your open-toe sandals and bare ankles!

    October 24, 2013 at 1:35 pm

  3. That explains the need for prednisone this summer. Awful stuff. Need a goat!

    October 24, 2013 at 1:38 pm

  4. Marilyn

    That’ll show ’em: More CO2 => more poison ivy! It IS beautiful… *shudder*

    October 24, 2013 at 9:34 pm

  5. Mary, That’s a damning statistic, isn’t it!? I was just noticing the other day how much sumac there is sprouting on our property here in Wentworth. I never used to see it here although it is native to the area. I wonder if the carbon theory explains why that is happening too? What a far-reaching effect this is proving to have!

    Thanks again Mary for your wonderful newsletter. Helen Downing

    October 25, 2013 at 6:37 pm

  6. My nemesis. Ugh. It only figures it likes CO2 and is becoming more potent

    October 27, 2013 at 12:31 am

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