16. Chenopodium pumilio R. Br. (clammy goosefoot)
Dysphania
pumilio (R. Br.)
Mosyakin & Clemants
Pl. 353 m, n;
Map 1536
Plants annual,
with a slight unpleasant odor. Stems 10–40 cm long, prostrate to loosely
ascending, few- to much-branched from near the base, with dense, short
glandular hairs, usually not reddish-tinged or reddish-striped, often appearing
pale green to nearly white. Leaves short- to long-petiolate. Leaf blades 0.5–3.0
cm long, those of well-developed leaves mostly 1.5–3.0 times as long as wide,
oblong-elliptic to ovate, mostly bluntly pointed at the tip, rounded or angled
at the base, mostly with few rounded lobes, occasionally nearly entire
(uppermost leaves), yellowish green and herbaceous in texture, the margins
usually also wavy or with shallow, blunt, narrow teeth, the surfaces lacking
mealiness, but with dense, sessile, yellowish resin glands. Venation noticeably
branched, usually with 1 main vein. Inflorescences axillary, consisting of
short spikes or small clusters of flowers. Flowers not all maturing at the same
time. Calyx 5-lobed nearly to the base, somewhat spreading at maturity and
exposing the fruit at maturity, the lobes 0.5–0.7 mm long, elliptic-ovate to
oblong-elliptic, usually sharply pointed at the tip, flat or more commonly
rounded to somewhat pouched dorsally, moderately to densely pubescent with
dense, sessile, yellowish resin glands, sometimes also with sparse to moderate,
short, nonglandular hairs. Stamen usually 1. Stigmas 3. Fruits 0.5–0.7 mm long,
ovoid, the seeds positioned vertically, the wall thin, membranous, and somewhat
translucent, smooth to finely and faintly wrinkled, difficult to separate from
the seed. Seeds reddish brown to dark brown, shiny, smooth, rounded along the
rim. 2n=16. August–October.
Introduced,
scattered, mostly in the southern third of the state (native of Australia;
introduced widely in the U.S., uncommonly in Canada). Banks of streams and
rivers, margins of sinkhole ponds; also crop fields, fallow fields, pastures,
farmyards, roadsides, railroads, and open, disturbed areas.