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 those found on the seeds of _Amaranthus circaezans_. There are three varieties with seeds much the same as these. Native of low ground in central and southern Michigan. [Illustration: Fig. 55.] =Prostrate Amaranth.= _Amaranthus blitoides_ S. Wats. Seeds smooth, highly polished, jet-black, double convex, nearly circular, with a slight notch at one edge, 1.4-1.5 mm. in diameter. Introduced from west of the Rocky Mountains. It thrives on sandy and gravelly banks. Margin of this seed is less pronounced than in either of the other three noticed above. Found almost everywhere in fields of Michigan. Introduced from tropical America. Very common in annual hoed crops. [Illustration: Fig. 56.] =Tumble weed.= _Amaranthus graecizans_ L. Seeds smooth, highly polished, jet-black, double convex, nearly circular with a slight notch at one edge, .7-1 mm. in diameter. Compare with _Acnida_. Introduced from tropical America. It needs sand or gravel. [Illustration: Fig. 57.]