This section is from the book "An Illustrated Flora Of The Northern United States, Canada And The British Possessions Vol2", by Nathaniel Lord Britton, Addison Brown. Also available from Amazon: An Illustrated Flora of the Northern United States, Canada and the British Possessions. 3 Volume Set..
Chenopodium murale L. Sp. Pl. 219. 1753.
Annual, scarcely or not at all mealy, somewhat scurfy above, stem erect or decumbent, usually branched, 1o-2 1/2o high, leafy to the summit. Leaves rhombic-ovate, thin, bright green on both sides, acute or acuminate at the apex, sharply and coarsely sinuate-dentate, broadly cuneate or subtruncate at the base, slender-petioled, 2'-4' long; flowers in loose axillary panicles shorter than the leaves, often not longer than the petioles; calyx-segments not entirely enclosing the utricle; styles short; seed sharp-edged, horizontal, firmly attached to the pericarp; embryo completely annular; stamens 5.
Chenopodium hybridum L. Sp. Pl. 219. 1753.
Annual, bright green, not mealy, sometimes more or less scurfy; stem slender, erect, usually branched, 2°-4 1/2o tall. Leaves ovate or rhombic-ovate, long-acuminate at the apex, truncate rounded or subcordate at the base, thin, slender-petioled, sharply dentate with 1-4 large acute teeth on each side, or the upper lanceolate and entire, the lower 4'-7' long; flowers in large axillary and terminal panicles; calyx about 1" broad, its segments oblong, rather obtuse, herbaceous, slightly keeled, incompletely covering the fruit; stamens 5; styles short; seed horizontal, sharp-edged, firmly attached to the pericarp; embryo a complete ring.
In woods and thickets, sometimes in waste places, Quebec to British Columbia, south to southeastern New York, Kentucky, Arkansas, Utah and New Mexico. Also in Europe. Sow-bane, Swine's-bane. July-Sept.
Chenopodium rubrum L. Sp. Pl. 218. 1753.
Blitum rubrum Reichb. Fl. Germ. Exc. 582. 1830-32.
Annual, glabrous, somewhat fleshy, not mealy, stem erect, leafy, 1°-2 1/2° tall, often much branched, the branches strict or ascending. Leaves thick, 1 1/2'-4' long, rhombic-ovate or rhombic-lanceolate, petioled, acute acuminate or obtuse at the apex, narrowed at the base, coarsely sinuate-dentate or the upper entire; flowers in erect compound leafy-bracted axillary and terminal spikes often exceeding the leaves; calyx 3-5-parted, its segments slightly fleshy, red, not keeled, obtuse, about as long as the utricle; stamens 1 or 2; styles short; seed horizontal, 1/2" wide, shining, rather sharp-edged, separating from the pericarp; embryo annular.
On the seacoast, Newfoundland to New Jersey, and in saline soil in the interior across the continent, south to central New York, Nebraska and British Columbia. Also in Europe and Asia. Swine's-bane. July-Sept.
Chenopodium h¨mile Hook., of similar situations, is lower, has flowers in axillary clusters and a smaller seed, and may be specifically distinct.