Lamb's-quarters (Chenopodium album), Chenopodiaceae

Lamb's-quarters description

Common lamb's-quarters (also known as white goosefoot) is an erect summer annual (up to 1 m tall) with a gray-mealy coating, particularly on the surfaces of younger leaves. This species has a lot of variability.

Propagation

Reproduction is by seed, and seedlings emerge in spring or early summer. Seeds are of 2 types - the most common can persist for years in the soil and are round, black, and 1-2 mm in diameter. A second seed type is less common, brown, slightly larger, oval and more flattened. This second type does not undergo an extended period of dormancy. Lambsquarters seeds normally germinate at a depth of only 0.5-3 cm below the soil surface.

Similar species

There are other weedy Chenopodium species, but none are widespread like common lambs quarter. The distinctive rhombic to egg-shaped to lanceolate leaves and gray-mealy coating distinguish common lambsquarters from other weed species. For example, kochia is also in the Chenopodiaceae (goosefoot) family, but kochia leaves are much narrower and do not have the gray-mealy coating.

Distribution

Common lambsquarters is common throughout the United States and much of Canada.

Identifying Lamb's-quarters

Seedling

Hypocotyls are green or tinged with maroon, smooth and fragile. Cotyledons are narrowly elliptic, about 12-15 mm long, dull green on the upper surface with maroon on the underside, becoming green with age. Young leaves have a gray-mealy coating, especially on the leaf undersides and the emerging leaves. The first pair of leaves are opposite; all others alternate. Margins of very young leaves are entire or have a few teeth. Stems of young seedlings are covered with mealy-white granules.

Juvenile plant

Lambs quarters identification at this stage can be made based on stems that are erect, branching, hairless, vertically ridged, often with maroon stripes. Leaves are petiolated, rhombic to egg-shaped to lanceloate, alternate, 3-10 cm long, and irregularly toothed. Some blades have a white-mealy coating, but this is restricted to younger leaves. Lower leaves on the lambs quarter weed are 2.5-7.5 cm long, almost always irregularly toothed.

Mature plant

As lambs quarters plants mature, the upper leaves are sometimes linear, lack petioles, and may have entire leaf margins.

Root structure description

Common lambsquarters plants have short and branched taproots.

Flowers

Flowers are produced from June to September on spikes grouped into a panicle arising from the ends of stems and the leaf axils. Individual flowers are inconspicuous, sessile, small, green, and aggregated into dense small clusters. The fruit is a utricle with a papery thin covering over a single seed. A single plant can produce thousands of seeds.

Post senescene

Erect woody stems and seedheads persist through the winter. Dead stems and remnants of the inflorescence are often red to purple.