Part 7

=Lady's Thumb.= Polygonum Persicaria L. Achene shining, jet-black, surface finely uneven, much flattened with rounded edges or with 3 nearly equal concave faces, the edges faintly angled along the center, broadly ovate, base obtuse or bearing a portion of the calyx, apex abruptly pointed, 2-2.3 long. Introduced from Europe. Waste places and stubble ground.

=Climbing False Buckwheat.= Polygonum scandens L. Achene black, shining, in cross-section sides flat or concave, corners rounded, obovate, in vertical outline sides rounded to an obtuse apex, from rounded sides to base slightly concave, base acute, 3.5-4 mm. long when freed from the persistent base of the calyx. Woods and shady places. Not prominent as a weed.

=Sorrel. Sour Dock.= Rumex Acetosa L. Calyx-wings broadly ovate or orbicular, heart-shaped 3.5-4.5 mm. long, achene shining, with 3 equal sides, broadly oval, both ends abruptly pointed, the thin edges usually lighter colored than the dark brown or black convex faces, 1.5-2 mm. long. Introduced from Europe. Not common.

=Sheep Sorrel.= Rumex Acetosella L. Achenes usually closely covered by dull reddish brown, finally roughened calyx, which is removed with difficulty; achenes shining with 3 equal sides, broadly oval, the base rounded, the apex abruptly pointed, sides convex, reddish brown or amber color, corners obtuse, darker colored. Native of this country, though in large part introduced from Europe. Very common in thin sandy meadows.

=Narrow-leaved or Curled Dock.= Rumex crispus L. Achene covered by 3 brown heart-shaped calyx-wings, which are 2.5-3.5 mm. long, each bearing an ovoid, acute tubercle; one of them is 1.5 mm. long, the other two smaller. Achene ovoid, 3-angled, shining, rich reddish-brown, 1.3-1.8 mm. long, .7-1.4 mm. wide, in transverse section the angles prominent, convex sides and angles concave near the base; base abruptly acute; when viewed vertically sides and angles concave near the apex; apex abruptly acute, compare these notes with those concerning R. obtusifolius. Introduced from Europe. Very common on low land and in meadows.

=Broad-leaved or Bitter Dock.= Rumex obtusifolius L. Achene covered by three brown, hastate-deltoid calyx-wings, which are about 4 mm. long, each bearing an ovoid-elliptical tubercle, one of them 1.5 mm. long, the other two very narrow, rudimentary. Achenes ovoid, 3-angled, less polished than those of R. crispus, light brown, 2-2.4 mm. long, 1-1.4 mm. wide, angles in transverse section slight, sides convex, usually in a greater degree than in the specie just named, vertically sides and angles very slightly concave or straight near the base which is abruptly acute; sides and angles near the apex scarcely concave or straight; apex acute. Introduced from Europe. Not very common.

=Patience Dock.= Rumex Patientia L. Calyx-wings circular-heart shaped, 4-6 mm. long, one of them bearing a prominent ovoid tubercle; achene ovoid-elliptical, 3-angled, somewhat polished, shining, light-brown, 2.5-3.5 mm. long, 1.7-2 mm. wide, angles prominent, sides straight, in transverse section, not counting the angles, base rounded, not counting the abrupt point, when seen vertically, the sides near the apex are straight or slightly concave. Introduced from Europe. Not common.

=Willow-leaved Dock.= Rumex Mexicanus Meisn. Rumex salicifolius Weinm. Calyx-wings triangular-ovate, about 3 mm. long, each bearing a large tubercle; achene dark reddish brown, smooth, shining, 1.8-2.2 mm. long, ovoid, angles prominent, the sides viewed transversely rounded, the sides of the base as viewed vertically, rounded, straight or slightly concave, near the apex straight or concave. A native of Northeastern North America. Not common.

GOOSEFOOT OR PIGWEED FAMILY. CHENOPODIACEAE.

=Spreading Orache.= Atriplex patula L. Seeds are likely to occur in either of three different guises, depending upon the degree of their ripeness or the amount of threshing to which they have been subjected.

Achenes thin, dull, granular, gray, closely fitting the seed; seed jet-black, shining, flattened, nearly circular, edge bluntly rounded, and notched in one place, a groove leading from one side of a margined protuberance part way to the center of the face, 1.5-1.8 mm. in diameter. Introduced from Europe. Seldom troublesome.

=Pigweed. Lamb's Quarters.= Chenopodium album L. Seeds are likely to occur in either of three different guises dependent upon the degree of their ripeness or the amount of threshing to which they have been subjected. The figure shows these conditions admirably.

Seeds black, dull or somewhat glistening, gray if not pretty clean; nearly circular; somewhat lens-shaped, one side usually more nearly flattened than the other 1-1.4 mm. in diameter, the edge bluntly rounded, the more convex side bearing a curved groove leading from one side of the marginal protuberance to near the center of the face, surface finely uneven, often with a faintly evident radiating striation. Introduced from Europe. Very common in annual crops.

=Mexican Tea.= Chenopodium ambrosioides L. Note remarks under last preceding description concerning different stages of cleaning. Seeds smooth, shining, reddish brown, to black, thickly double convex with scarcely a trace of a hem-like margin, circular, short kidney-shaped or ovate with a notch on the edge, .6-.8 mm. long. Introduced from tropical America. Not prominent.

=Jerusalem Oak.= Chenopodium Botrys L. Concerning different states of cleaning, note remarks above under C. album.

Seeds perfectly cleaned with great difficulty, brown to black or gray, when imperfectly cleaned, slightly flatted on two sides, circular or round, kidney-shaped, sometimes with a hem-like margin, on one side a faint groove from the margin to near the center of the face, .6-.8 mm. in diameter. Introduced from Europe. Not prominent.

=Oak-leaved Goosefoot.= Chenopodium glaucum L. Concerning the different stages of cleaning note remarks above under C. album.

Seeds brown to black, more or less slightly granular, shining, flattened on two sides, circular edge bluntly rounded, with a single notch from which on one side extends a slight depression toward the center of the face, .5-.8 mm. in diameter. Introduced from Europe. Occasional on moist soil.

=Maple-leaved Goosefoot.= 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.

=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.

=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.

=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.

=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.

=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.

=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.