Common lambsquarters (Chenopodium album L.) is a common weed of many agronomic and vegetable crops.  You may have come across this weed in your garden while you were weeding.  Common lambsquarters can also grow on lawns or on disturbed sites, both on acidic and alkaline soils.  This weed can be found widely throughout the United States.

This weed is  a summer annual and it’s most notable feature for identification is the gray-mealy speckling on the surfaces of younger leaves.  This gray speckling can be especially seen on the leaf undersides and the emerging leaves.  When the plant is mature the stems are erect, branching, hairless, vertically ridged and may have maroon striping.  The root system is a short, branched taproot.

Common lambsquarters produce flowers from June to September which arise from the ends of stems and leaf axils.  Individual flowers are inconspicuous, close to the stem, small, green, and aggregated into dense small clusters.  Seeds of this weed can persist in soil for years however they do not undergo an extended dormancy period.  A single plant is capable of producing thousands of seeds.  For more information on how to control this weed, watch this video from AgPhD.

Resource:  Uva, Richard H., Joseph C. Neal, and Joseph M. DiTomaso. Weeds of the Northeast. Ithaca: Comstock Pub. Associates, 1997. Print.