Possible hogweed

Asked June 14, 2019, 2:19 PM EDT

This plant came up this year and my son said he thinks it might be Giant Hogweed. Is there any way you might be able to identify it for me? I understand it is a very dangerous plant help.

Lapeer County Michigan weed issues

2 Responses

Hello,

Thank you for the clear pictures. This may be giant hogweed, or a smaller weed called cow parsnip. Some people are sensitive to cow parsip, but it is not as dangerous as the hogweed.

Please e-mail photographs of the plant, leaves, flower head and stem where the leaf joins the stem, to Michigan State University Diagnostic Services at pestid@msu.edu for confirmation. You will receive a response letting you know whether the plant is giant hogweed.

Giant hogweed’s stems are 2- 4 inches in diameter, while cow parsnips reach up to 2 inches diameter. Also, present on both leaf surfaces, the soft hairs are primarily confined to the lower leaf surface of cow parsnip and have a velvety appearance. These lower leaf hairs on cow parsnip are about 1 mm long and are often the best distinguishing characteristic from giant hogweed. The flower top when fully open on cow parsnip looks flat, while giant hogweed’s flower is rounded on top. See the links for pictures and size differences.

These references have pictures and info on how to remove it-

https://www.canr.msu.edu/uploads/files/E2935_2012_Revision.pdf

https://www.inhs.illinois.edu/files/8314/9848/6126/Hogweed_and_Lookalikes_2017.pdf

Michigan Invasive Species Information Network reporting- you may report it if it is giant hogweed-

https://www.misin.msu.edu/facts/detail/print.php?id=23

Remember to use all precautions around it until ID is confirmed, and don’t let it touch pets, either. Thank you.

One additional note, if you can safely add an object in a photo to show the size of the stem or leaf, that helps. A ruler, a pen, etc.Thanks