Lamb's-quarters, Chenopodium album

Life Cycle

Annual

Propagation

Reproducing only by seed.

Stems

Stems are 20-200cm high, branched or unbranched, smooth, green or with reddish or purplish lengthwise stripes and ridges.

Leaves

First 2 or 4 true leaves apparently opposite (2 per node), but all later leaves and branches distinctly alternate (1 per node); leaves stalked, the blades 3-10cm long, lance-shaped or more often broadly triangular with irregular, usually shallow teeth; leaves green or grayish due to a covering of a white mealiness or powderiness, sometimes with reddish undersurface on young plants.

Flowers and Fruit

Flowers very small, greenish, densely grouped together into small, thick, granular clusters along the main stem and upper branches, having 5 green sepals but no petals; seeds small, rounded in outline, somewhat flattened, 1-1.5mm in diameter, enclosed in a very thin, membranous, smooth, whitish covering (pericarp) which is readily fractured and lost when dry. Flowers from June to August. [f5]

Roots and Underground Structures

Fibrous root system.

Habitat

Lamb's-quarters is very widespread throughout Canada, occurring in cultivated fields, pastures, wasteland, roadsides, gardens and almost anywhere the soil is disturbed.

Competitiveness

Corn yield loss (%)*: 12 % at 1 plant/m2 35 % at 5 plant/m2 Soybean yield loss (%)*: 13 % at 1 plant/m2 38 % at 5 plant/m2 *assumes that the weed has emerged with the crop and has been left uncontrolled all season.

Distinguishing Features

It is distinguished from the Atriplexes by having only the first 2 or 4 leaves arranged in opposite pairs, and from most other weeds by its broadly triangular leaves with irregular, shallow teeth, its smooth, occasionally mealy or scurfy leaves and stem, and its inflorescence of small, greenish flowers in granular clusters.

Toxicity

Lamb's-quarters is not known to be toxic. The leaves are edible.

Human Health Issues

Lamb's-quarters is not a known allergen.

Forage Quality

No information exists at this time.

Species Benefits

"The tender leaves and tips are excellent steamed or boiled. The highly nutritious seeds can be boiled to make a breakfast gruel, or ground into flour." From: Peterson, LA, 1977, A Field Guide to Edible Wild Plants of Eastern and Central North America, Houghton Mifflin Company, New York. http://www.youtube.com/watch?v=l021TdYC7iQ to view a recipe for "Lamb's Quarter Quiche"

Often Mistaken For

Spreading atriplex (ATXPA), Oak-leaved goosefoot (CHEGL)

Power Ranking Corn

Power Ranking

↑ 2

 

Power Ranking Soybeans

Power Ranking

↑ 2

 

Biological Control

Currently none available for this weed. For the latest research on biological weed control: http://res2.agr.ca/Lethbridge/weedbio/index_e.htm#toc

Biopesticide Control

Currently none available for this weed in corn and soybean.

Herbicide Resistance

Sulphonylurea and imidazolinone resistant (WSSA group 2) populations exist in Elgin , Kent, Middlesex and Simcoe counties (ON). Triazine resistant (WSSA group 5) populations exist throughout Ontario. For more information on weed resistance: http://www.plant.uoguelph.ca/resistant-weeds/


Figure #1.

Lamb's quarters. A. Young flowering plant. B. Seedling in 2nd true-leaf stage, top and side views. C. Seedling in 6th true-leaf stage.


Figure #2.

Lamb's-quarters at the 2-leaf stage.


Figure #3.

Lamb's-quarters at the 8-leaf stage.


Figure #4.

Lamb's-quarter leaf.


Figure #5.

Flower head of lamb's-quarters.


Figure #6.

A mature lamb's-quarter plant.