17. Chenopodium rubrum L. (coast blite, red goosefoot)
C. rubrum var. humile (Hook.) S. Watson
Pl. 356 l, m;
Map 1537
Plants annual,
without an odor. Stems 20–80 cm long, erect or ascending, few- to much-branched
from near the base, glabrous, often somewhat reddish-tinged or reddish-striped.
Leaves short- to long-petiolate. Leaf blades 1–10 cm long, mostly 1–2 times as
long as wide, ovate-triangular to somewhat rhombic, bluntly to sharply pointed
at the tip, angled or tapered at the base, sometimes with a pair of more or
less ascending triangular basal lobes, green and slightly fleshy in texture,
the margins otherwise entire, wavy or with few to several blunt, irregular
teeth, the surfaces glabrous. Venation noticeably branched, with 1 or 3 main
veins. Inflorescences axillary and sometimes also terminal, consisting of dense
clusters of flowers (remaining 3–5 mm in diameter at fruiting), the terminal
ones usually arranged into spikes, these sometimes grouped into small panicles.
Flowers not all maturing at the same time. Calyx 3(–5)-lobed nearly to the
base, remaining small, green, and herbaceous to scalelike at maturity, more or
less covering the fruit at maturity, the lobes 0.9–1.2 mm long, oblong-elliptic
to oblong-lanceolate, rounded to bluntly pointed at the tip, rounded or
somewhat pouched dorsally, rarely slightly keeled, glabrous or sparsely
white-mealy. Stamens usually 3–5. Stigmas 2. Fruits 0.7–1.2 mm long, ovoid, the
seeds positioned mostly vertically, the wall thin, membranous, and somewhat
translucent, smooth, easily separated from the seed. Seeds reddish brown to
dark brown, shiny, finely roughened and/or with a faint network of fine, low
ridges, angled along the rim. 2n=36. July–November.
Introduced,
uncommon and sporadic (native of eastern North America, Europe, Asia;
introduced sporadically elsewhere in the U.S.). Roadsides and open, disturbed
areas.
Several variants
have been named within this species. Bassett and Crompton (1982), who studied C.
rubrum in Canada, suggested that these varieties represented merely
ecological forms unworthy of formal taxonomic recognition. The few Missouri
specimens key to var. rubrum, because of their relatively small seeds,
ascending stems, well-developed inflorescences, and toothed leaves. The limits
of the range of C. rubrum are not understood fully, and it is unclear
how far west in the United States the species grows natively. However, the few
specimens from Missouri all clearly all originated from introduced populations.