This week in Sidewalk Botany:

Horseweed and Crabgrass

Conyza canadensis

A resilient native plant and an escaped forage crop!

Horseweed aka Conyza canadensis Horseweed is a common native plant that is very likely to spring up in your lawn if you stop mowing. Many insects feast on the pollen and nectar of the teeny tiny flowers. Horseweed was declared an agricultural weed because it does well in disturbed soil such as freshly tilled agricultural land and competes with cash crops. It was one of the first plants to develop a resistance to glyphosate! Inspiring, right?! Indigenous people have used it to treat sore throat and dysentery. I see horseweed popping up in an area of the yard that I have stopped mowing. I’m letting it grow in one area and pulling it from another because it inhibits the growth of Asters.

Digitaria sanguinalis

Even, I, a person who professes a nonjudgmental look at weeds, feels pretty put off by crabgrass. It has the amazing ability to colonize the surface of the soil with its low growth pattern- it shoots out seed heads that rest expectantly on the soil. It is native to Europe or Eurasia but is widespread throughout the globe now. Crabgrass was introduced as a forage crop by the US patent office in 1849. Other varieties of Digitaria, like those found in Africa, have been used to make flour and even beer! 

Sidewalk Botany is a weekly series of explorations of our photosynthesizing neighbors written by Planet Detroit’s Artist-in-Residence, Bridget Quinn of the A.W.E. Society. To get started identifying plants around you, join us on the Detroiters Do Science project on I-Naturalist.