9.
Chenopodium simplex
(Torrey) Rafinesque, Atlantic J. 1: 146. 1832.
Maple-leaf goosefoot
Chenopodium hybridum
Linnaeus var.
simplex
Torrey, Ann. Lyceum Nat. Hist. New York 2: 239. 1827;
C. gigantospermum
Aellen,
C. hybridum
subsp.
gigantospermum
(Aellen) Hultén,
C. hybridum
var.
gigantospermum
(Aellen) Rouleau
Stems
erect, branched, 3-15 dm, glabrous.
Leaves
nonaromatic; petiole 0.15-0.45 cm; blade ovate to triangular, 3.5-15 × 2-9 cm, base cordate to truncate, margins sinuate
-
dentate with 1-5 coarse, acute teeth, distal leaves entire or with few small teeth, apex acute, glabrous.
Inflorescences
glomerules in terminal and lateral spikes and panicles, 6-15 cm; glomerules irregularly globose, flowers in different stages of development, 0.5-2 mm diam.; bracts absent.
Flowers:
perianth segments 5, connate into 0.5 mm tube; lobes ovate to lanceolate, 0.7-1 × 0.4-0.6 mm, apex retuse, slightly keeled, glabrous, margins meeting or separated by as much as their width, exposing more than
1
/2 fruit at maturity; stamens 5; stigmas 2, 0.1 mm.
Achenes
depressed-ovoid; pericarp adherent, chartaceous, smooth.
Seeds
lenticular, 1.3-1.9 mm diam.; seed coat black, indistinctly honeycombed to nearly smooth, margins rounded.
2
n
= 18.
Fruiting Jul-Oct. Woods, thickets, hardwood slopes, wooded tallus, nutrient-rich woods, sometimes in waste places and fields; 0-1800 m; Alta., B.C., Man., N.B., N.W.T., N.S., Ont., Que., Sask., Yukon; Alaska, Ark., Calif., Colo., Conn., Del., Idaho, Ill., Ind., Iowa, Kans., Ky., La., Maine, Md., Mass., Mich., Minn., Mo., Mont., Nebr., Nev., N.H., N.J., N.Mex., N.Y., N.C., N.Dak., Ohio, Okla., Pa., R.I., S.Dak., Tenn., Tex., Utah, Vt., Va., Wash., W.Va., Wis., Wyo.
A closely related Eurasian diploid species,
Chenopodium hybridum
Linnaeus, probably also occurs in North America as introduced. Its occurrence in the New World needs confirmation.
Chenopodium simplex
differs from its Eurasian counterpart in having a smoother seed coat, a yellowish pericarp that is more adherent to the seed, and a different chromosome number (A. I. Baranov 1964; R. D. Dorn 1988b).
