Beware of poison hemlock, wild parsnip and poison ivy this summer

One of the joys of summer is getting out and enjoying nature, but not all nature’s entire flora plays fair.
In Iowa, including Montgomery County, humans need to be aware of wild parsnip, poison ivy, poison hemlock and stinging nettles. Montgomery County Weeds Commissioner Damien Bond said all four weeds are at “full bore” currently. Bond has served as weed commissioned in Montgomery County for more than 20 years.
“The wet, cool temperatures this spring really helped them take off,” said Bond.
The most infamous of the four weeds is poison hemlock. A member of the wild carrot family, Bond said poison hemlock resembles Queen Anne’s Lace with large, white flowers. He added it usually grows in large clusters in moist, open areas along roadsides, stream banks, irrigation ditches, hiking trails and railroad right-of-ways.
Standing as tall as 10 feet, with a smooth light green stem with purple spots or streaks, Bond said repeated mowing will eventually kill the poison hemlock, as well as the usage of 2-4-D. The younger the plant, the easier it is to kill, Bond added.  
It is a biennial weed that doesn’t flower the first year of growth but flowers the second year. It is found across the United States and contains highly toxic piperidine alkaloid compounds, including coniine and gamma-coniceine, which cause respiratory failure and death.
Bond said the roots are more toxic than the leaves and stems but all parts of the plant, including the seed, are dangerous.
To induce poisoning, poison hemlock toxins must be ingested or enter through the eyes or nasal passages. Regardless, this plant should not be handled because sap on the skin can be rubbed into the eyes or accidentally ingested while handling food.
“It is easily identifiable and has a rank odor associated with it when it’s blooming,” Bond described.
Bond said he actively treats poison hemlock and asks county residents to contact the county engineers office at 712-623-5197 if they see a patch on right of way adjacent to homes or county property. If on private property, Bond said landowners are asked to destroy it.
“Poison hemlock over the years has seemed to be the more aggressively growing one. I’ve seen it spread each year. I can’t be everywhere all the time, so it’s helpful when people let me know where they see it.”
Poison hemlock isn’t just dangerous to people, it can also be deadly to animals.
Bond said for the most part, livestock like cattle and horses will avoid it unless the grazing area has been overgrazed and it’s the only thing left to eat.
All parts of the plant are toxic to domestic livestock – even when it is dry, like in hay.
All parts of the plant are toxic.
Another relative that is poisonous is wild parsnip, which looks similar to poison hemlock, but has yellow flowers. However, wild parsnip prefers sunny areas like pastures and roadsides but will also inhabit low-lying areas. Wild parsnip plant parts contain a substance called psoralen, which can cause a condition known as “phytophotodermatitis.” This reaction occurs when plant juice gets on the skin and the skin is exposed to sunlight. The results are skin reddening, rash development, and in severe cases, blisters and burning or scalding type pain.
If its oil touches the skin and then is exposed to sunlight, painful blisters will develop. It doesn’t matter if the plant is flowering or not - avoid contact with it at all times. If exposed, wash it off as soon as possible.
Golden Alexander is often confused for Wild Parsnip, said Bond, but included there are no issues with the Golden Alexander.
Leaves of three, let it be is the motto of poison ivy, which causes severe skin irritaion for weeks on end.
With Poison Ivy, each leaf has three parts or leaflets. Bond said leaves are often glossy and may show bumps or other deformities. A short plant along the grount, the flowers of poison ivy are green-white and produce white berries. The poisonous oil covers all parts of the plant, including the roots. Bond said burning the weed might seem like a good idea, but is not, as it can be carried on smoke. He added poison ivy oil spreads from dead poison ivy plants, too, and can be picked up from other objects that touch the plant, such as fur of a pet.
“Poison Ivy seems to affect me more as I get older,” said Bond. “I try to keep myself protected as much as possible when working with these type of weeds.”
Lastly, during the summer it’s best to avoid stinging nettles, which is just what the name advertises. Plant hairs inject acid into the skin when brushed up against it. However, the reaction is less severe than with wild parsnip or poison ivy.