21. Chenopodium urbicum L. (city goosefoot)
Pl. 356 j, k;
Map 1541
Plants annual,
without an odor. Stems 20–80 cm long, erect or ascending, usually not or
few-branched above the base, glabrous or sparsely white-mealy, green to pale
green. Leaves mostly long-petiolate. Leaf blades 2–11 cm long, mostly 1–2 times
as long as wide (1–10 cm wide), mostly ovate-triangular, sometimes ovate or
rhombic, the uppermost lanceolate to narrowly triangular, bluntly to sharply
pointed at the tip, angled to truncate at the base, green, relatively thin and
herbaceous in texture, the margins wavy or irregularly several-toothed (the
basal pair of teeth usually larger than the others), the upper surface glabrous
and usually shiny, the undersurface sparsely to moderately white-mealy.
Venation noticeably branched, with 1 or 3 main veins. Inflorescences axillary
and terminal, consisting of short spikes with small clusters of flowers, the
terminal ones usually grouped into small to relatively large panicles. Flowers
not all maturing at the same time. Calyx 5-lobed nearly to the base, extending
past the widest part of the fruit but not reaching the stylar area, leaving
much of the portion of the fruit above the rim exposed at maturity, the lobes
0.6–0.8 mm long, elliptic to broadly ovate, rounded or bluntly pointed at the
tip, flat or somewhat rounded dorsally, glabrous or sparsely white-mealy.
Stamens 5. Stigmas 2. Fruits 0.9–1.2 mm wide, depressed-ovoid, the seeds
positioned horizontally, the wall thin, membranous, and somewhat translucent,
smooth or finely roughened at maturity, usually easily separated from the seed.
Seeds reddish brown to black, shiny, finely wrinkled or appearing nearly smooth
at maturity, rounded to very bluntly angled along the rim. 2n=36. July–October.
Introduced,
uncommon and sporadic (native of Europe, Asia; introduced widely in portions of
the northern and western U.S., Canada). Bottomland forests and banks of rivers;
also pastures, railroads, and open to shaded disturbed areas.
The reports by
Steyermark (1963) from Boone and Greene Counties could not be confirmed during
the present research.