Chenopodium hybridum_ L. Concerning the
different stages of cleaning, note remarks above under C. album.

Seeds black, shining, greenish gray if not fully cleaned, nearly
circular, lens-shaped, equally convex, 1.2-1.8 mm. in diameter, with a
notch on the edge, from which on one side a groove leads to near the
center of the face, surface finely uneven, often with a faintly evident
radiating striation. Native of this country. Of little importance.

[Illustration: Fig. 51.]

=Many-seeded Goosefoot.= _Chenopodium polyspermum_ L. Concerning
different stages of cleaning, note remarks above under C. album.

Seeds finely glandular, shining, jet-black, greenish gray, when not
fully cleaned, nearly circular or broadly kidney-shaped, sides equally
convex, .6-1.1 mm. in diameter, with a notch on the edge from which on
one side, a groove leads to near the center of the face. Introduced from
Europe.

[Illustration: Fig. 52.]

=Winged Pigweed.= _Cycloloma atriplicifolium_ (Spreng.) Coulter. Seeds
are likely to occur in either of three different guises depending upon
the degree their ripeness or the amount of threshing to which they have
been subjected. See the figure of this species. Seeds granular,
circular, dull, jet-black, or gray in case the thin ovary remains,
1.3-1.7 mm. in diameter, lower face convex, the upper slightly convex if
mature, with a slight notch on the rounded edge, the lower face bearing
a slight curved groove, leading from the notch to near the center, the
upper face with a light spot at the center. Introduced from western
United States. A tumble weed, not common.

[Illustration: Fig. 53.]

=Russian Thistle.= _Salsola Kali tenuifolia_ G. F. W. Mey. This is not a
thistle nor a cactus, but a pigweed. Concerning different stages of
cleaning, note remarks above under Chenopodium album (see the figures).
Seeds conical, the apex flattened or concave, both sides showing the
long coiled embryo, light gray in color, about 2 mm. in diameter.
Introduced from northern Europe into the north west and from there into
Michigan. Well advertised, though not of high rank as a weed in this
state. A tumble weed.

AMARANTH FAMILY. AMARANTHACEAE.

[Illustration: Fig. 54.]

=Western Water Hemp.= _Acnida tuberculata Moq._ Seeds smooth, highly
polished, brown to jet-black, double convex, nearly circular, with a
slight notch at one edge, .6-.8 mm. in diameter, smaller, lighter
colored, and thin margins less conspicuous than