Pigweed in pastures

Asked July 23, 2019, 3:38 PM EDT

Hi, I have horses on pasture. I have what appears to be several versions of pigweed in the pasture. One is the version in attached picture. Am I correct to call this "prostrate" pigweed? If so, is it particularly dangerous to horses? What types of pigweed are particularly dangerous and how do I ID them?

Washtenaw County Michigan horses horse pasture management

1 Response

The plant in the photo is called oak-leaved goosefoot (Chenopodium glaucum). This is an introduced annual species in Michigan. It is in the Amaranth/Pigweed family.

Some information on the toxicity of plants in this genus can be found at the following link from Colorado State University
https://csuvth.colostate.edu/poisonous_plants/Plants/Details/75

Based on that information it looks like large quantities would need to be consumed to cause concern.

There is a key available to ID plants in the Amaranth family on Michigan Flora at
https://www.michiganflora.net/family.aspx?id=Amaranthaceae unfortunately this can be quite cumbersome to work through. I would suggest trying the plant ID app called PictureThis (https://www.picturethisai.com/). The app will try to push you to pay for the premium version, but if you keep "X-ing" out of the pop-up windows then you can use the free version.