Weed of the Week: Italian Arum (Arum italicum)
Before we start on this weeks weed; Italian Arum, let’s discuss what a noxious weed is. A noxious weed is a non-native plant (typically) that can have a determination effect on the environment. Typically that effect starts with pushing out native plants. Removing native plants and replacing them with non-natives will effect other plants, insects, birds, amphibians, and up the food chain to mammals. Noxious weeds have many ways of taking habitat away from native plants, some release chemicals, some produce 1000’s of seeds that survive 10+ years in the soil, some physically overtake native plants and trees. In this week’s case, Italian Arum typically crowds out native plant, stealing their light and water.
Today we will discuss Italian Arum, a beautiful and yet potentially deadly plant. Yes, I did say DEADLY! The plant contains calcium oxalate crystals which can cause skin and eye irritation if it comes in contact with your eyes or skin. If ingested it will cause mouth pain/swelling, vomiting, diarrhea and even death if not treated. This is why is it listed as a weed of concern in areas where it occurs or is likely to occur. The plant is dangerous to pets, livestock and people alike. Luckily it is bitter tasting and most animals will not eat it but children should be supervised when near the plant. Extra care should be taken when you are gardening near this plant as well.
Italium Arum prefers shady wooded areas, but I have seen it growing in sunny grassy fields as well. It does require a high amount of soil moisture and therefore is commonly found near creeks and streams. It is particularly detrimental plant for riparian areas where is will spread quickly and crowd out important native plants.
Removal and control is very difficult and this is one of the reasons why it is important we control it as soon as it is spotted. Seeds speed from the brilliant red fruits, new plants grow from the tubers underground and soil disturbance only encourages more growth. The leaves have a waxy coating where makes chemicals much less effective. Digging it up is really only recommended if you have a small patch, mechanical removal of large patches only promotes distribution and growth. I also recommend you contact your local weed board, often these agencies have programs (and $) to assist you in eradicating noxious weed from your property. If you have a small plant or patch wear gloves and eye protection and dig it up. Try to get all the roots/tubers and place all material in thick trash bags. DO NOT COMPOST any part of the plant!
I hope this article gave you a better understanding of this dangerous and toxic plant. Keep your eyes open for it and report it if you find it to land owners or local agency,
Consult your local Weed Board for more information on removal and eradication specific to your area.