Part 2

=Large Crab-Grass. Finger Grass.= _Digitaria sanguinalis_ (L.) Scop. _Panicum sanguinale L. Syntherisma_ (L.) Nash. Spikelets before severe rubbing, oblong, acute, 2.5-3.5 mm. long, first glume on flattened side minute, second on rounded side about half as long as the spikelet, pubescent or nearly smooth, third glume more or less pubescent, 5-7-nerved; floret, after severe rubbing, smooth, edges of floral glume thin. Introduced from Europe. Roots very tough and coming from the lower joints.

=Barnyard Grass.= _Echinochloa Crus-galli_ (L.) Beauv. _Panicum Crus-galli_ L. Florets oval, white, yellowish gray or brown, 2.4-3 mm. long, plano-convex, glume on the convex side, highly polished, three obscure longitudinal nerves. Native of this country.

=Yard-Grass. Wire-Grass.= _Eleusine Indica_ (L.) Gaertn. Florets light lead color or brown before threshing or much rubbing; grain dark, reddish brown, 1.2-1.4 mm., ovoid with the base abruptly pointed, 3 sided, the corners rounded, a vertical groove along one side; seen from the back with the groove side down and base toward the observer, starting from an oval spot near the base, 10-15 ridges on each side, extend downward and forward. Introduced from some warmer region of the Old World.

=Stink-Grass.= _Eragrostis megastachya_ (Koeler) Link. _Eragrostis major_ Host. Grain orange red or wine color .4-.6 mm. long. Broad oval to nearly circular, very slightly flattened, extremities slightly pointed, embryo within one edge near the base, a fine network of dark lines evident under a good lens. Introduced from Europe.

=Squirrel-tail Grass.= _Hordeum jubatum_ L. Spikelets in clusters of three, central one only fertile, 5 mm. long, containing a grain adhering to the floral glume and palea, the other two abortive, seven awns in these three spikelets, 4-6 cm. long, four others less than 1 cm. long; awns and fragment of rachis holding the cluster of spikelets together, all barbed upward, making them troublesome for fleeces of sheep and the mouths of animals eating them. Native of this country and widely distributed.

=Old Witch Grass. Tickle Grass. A Tumble-Weed.= _Panicum capillare_ L. Florets flattened, elliptical, apex abruptly pointed, about 1.5 mm. long, highly polished, leaden gray, lighter at the extremities and along the edges of the glume, five slender light colored nerves join the extremities passing vertically over the glume, two light nerves on the palea. Native to this country.

=Tall Smooth Panicum. Switch Grass.= _Panicum virgatum_ L. Achene surrounded by two persistent shining pieces, the floret; floral glume hard, light brown, oval or ovate-lanceolate 2.5-3.1 mm. long. Apex obtusely pointed. Seldom troublesome, widely distributed.

=Low Spear-Grass.= _Poa annua_ L. Florets straw-colored, 2.8-3.1 mm. long, apex smooth, lower half of keel and the base of lateral nerves, having numerous soft hairs. A low annual grass, introduced from Europe.

=Flat stemmed Poa. Wire Grass. Canadian Blue Grass.= _Poa compressa_ L. Florets lance-obovate, 2-2.5 mm. long, closely resembling those of Poa pratensis, which see.

Palea abruptly acute. If well rubbed after threshing, the floret is nearly smooth, otherwise it contains on the lower half numerous webby hairs. Grain reddish brown, both ends pointed, 1-1.4 mm. long. Seldom sown purposely. Sometimes used to adulterate Poa pratensis. In early days this grass was called blue grass by people of New England and New York State. Introduced from Europe.

=June Grass. Kentucky Blue Grass.= _Poa pratensis_ L. Florets ovate-lanceolate, acute 3-4 mm. long, with three equal sides when seen in transverse section, nearly smooth, if severely rubbed in threshing, otherwise the floral glume is thickly webbed at the base; palea acuminate, grain light brown, elliptical, both ends usually pointed 1.2-1.4 mm. long, in cross sections with three equal sides, one of which has a shallow vertical groove. Compare with Poa compressa. Introduced from Europe.

=Rye.= _Secale cereale_ L. Grain light brown, 6-8 mm. long, elliptical, base acute, apex obtuse and rounded, in cross section the back somewhat acutely rounded, the opposite side with a narrow vertical groove, surface more or less irregularly wrinkled. Introduced from Europe. A bad weed in wheat fields.

=Pigeon-Grass. Yellow Foxtail.= _Setaria glauca_ (L.) Beauv. _Chaetochloa glauca_ (L.) Scrib. Spikelets light to dark brown, 2.5-3 mm. long; after threshing or much rubbing consisting of each a grain and two firm coverings, known as a floral glume which covers the sides of the somewhat depressed palea, oval, apex slightly 3-toothed, rounded side strongly arched, somewhat V-shaped, roughened crosswise by prominent fine more or less branching ridges; ridges of palea on concave side less prominent. Introduced from Europe. Very common in hoed annual crops.

=Green Foxtail. Green Pigeon Grass.= _Setaria viridis_ (L.) Beauv. _Chaetochloa viridis_ (L.) Nash. Spikelets, light to dark brown mottled, 2-2.3 mm. long, after threshing or much rubbing consisting of the grain and two firm coverings, the rounded one known as a floral glume which covers the edges of the flattened side, oval, the surface granular and very faintly striate, lengthwise and ridged crosswise. Much resembling Hungarian grass. Introduced from Europe. Found with yellow foxtail.

=Porcupine Grass.= _Stipa spartea_ Trin. Grain inclosed in the floral glume, light brown, 18 mm. long, clothed on the lower half with short brown hairs slanting upward, bearing at the base a sharp, hard, curved beak, when dry the attached awn is twisted for 6 cm. and straight and bent at right angles about 6 cm. When moistened, the awn untwists more or less; twisting and untwisting the beards hold what the beak pierces, thus making it a formidable weapon to enter the skins of sheep, goats and dogs. Fortunately it is seldom abundant. Sandy land Michigan and westward.

SEDGE FAMILY. CYPERACEAE.

=Yellow Nut-Grass.= _Cyperus esculentus_ L. This is a species of sedge, and so far as I have examined, produces no seeds, perhaps having lost that method of reproduction, as it acquired the habit of spreading by tubers here illustrated. In moist soil, sometimes a troublesome weed.

=Ovoid Spike-rush.= _Eleocharis ovata_ (Roth.) R. & S. Spike ovoid, 4-10 mm. long, achene pale to chestnut brown, shining, obovate-oblong, compressed, about 1 mm. long, bearing a triangular tubercle at the apex, and six to eight barbed bristles, 1.3-1.7 mm. long, very variable. Not troublesome except in low land.

RUSH FAMILY. JUNACEAE.

=Slender Rush.= _Juncus tenuis_ Willd. Seeds light brown to amber color, translucent, flattened, oval, half oval, oblong, ovoid, the acute apex curved to one side, about 0.3 mm. long. Dry to moist soil, almost throughout North America, now migrating to all parts of the world. A very common, grass-like rush in this state, seldom recognized by any one under any name, except by a first-rate botanist.

LILY FAMILY. LILACEAE.

=Field Garlic. Wild Garlic.= _Allium vineale_ L. Seeds not seen, apparently seldom produced; bulblets (b) light yellow or almost white, obovoid to elliptical, 7-8 mm. long, when dry. Introduced from Europe. Troublesome in pastures and tainting the flavor of butter; in wheat it taints the flavor of flour. Persistent when introduced. The illustration of grains of wheat (a) are given for comparison.

NETTLE FAMILY. URTICACEAE.

=Slender Nettle.= _Urtica gracilis_ Ait. Achenes compressed, lens-shaped, ovate, rarely oval, faces similar, smooth, dull and grayish brown, .9-1.1 mm. long. Native of this country. Compared with U. dioica, this achene is thinner and shorter. Prominent in low pastures.

BUCKWHEAT FAMILY. POLYGONACEAE.

=Knot-Grass.= _Polygonum aviculare_ L. This door-yard weed is in no sense a grass. Achenes unequally 3-sided, ovoid, acute, angles obtuse, surface, dull, light to dark reddish brown, finely granular and striate lengthwise. 1.8-2.2 mm. long, usually with the remains of calyx attached. Native of this country. Common about door-yards.

=Wild Buckwheat.= _Polygonum Convolvulus_ L. Achenes dull, jet-black, equally 3-sided, elliptical to obovoid, minutely granular often with faint longitudinal striation, the faces often more or less concave, the angles rounded, 2.5-3.5 mm. long, sometimes with the remains of calyx attached. Introduced from Europe. Often climbing up corn stalks.

=Erect Knotweed.= _Polygonum erectum_ L. Achenes dull, light to dark brown, unequally 3-sided, ovoid or rhombic, finely granular and striate lengthwise, the faces sometimes concave, the angles rounded, 2.5-3 mm. long, sometimes with the remains of calyx attached. Native to this country. Of little account.

=Smart-weed.= _Polygonum Hydropiper_ L. Achene dull, granular, light to dark reddish brown, lenticular, acutely and narrowly or broadly elliptical, or 3-sided, apex acute, concave on the sides, angles obtuse, 2-3 mm. long, sometimes with the remains of the dotted calyx attached. Introduced from Europe. Wet land.

=Dock-leaved or Pale Persicaria.= _Polygonum lapathifolium_ L. Achene shining, dark to chestnut brown, 2-2.2 mm. long, flattened, circular to broadly ovate with abruptly pointed apex, the base obtuse or bearing the remains of the thin calyx. Introduced from Europe. Low wet places.

=Shore Knotweed.= _Polygonum littorale_ Link. So far as the achenes are concerned, they are identical with those of P. aviculare above described. Native of this country. On hard or thin places, especially when newly graded.

=Pennsylvania Persicaria=, _Polygonum Pennsylvanicum_ L. Achene shining, jet-black, flattened, surface very slightly uneven and granular nearly circular with a short abrupt apex, edge rounded, 2.5-3 mm. long, often bearing the remains of the calyx. Native to this country. Occasional in annual crops.

=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.

=Slender Pigweed.= _Amaranthus hybridus_ L. (_A. chlorostachys_). Seeds smooth, highly polished, jet-black, double convex, broadly ovate, with a slight notch at the narrow extremity, 1.1-1.4 mm. long. Distinguished from the preceding species by having a seed ovate instead of circular. Introduced from tropical America. Not abundant.

=Rough Pigweeds.= _Amaranthus retroflexus_ L. Sometimes incorrectly called red-root. Seeds smooth, highly polished, jet-black, double convex, broadly ovate, with a slight notch at the narrow end, .9-1.2 mm. long. The seeds of this and the next preceding are ovate, while those of the first two are very nearly circular. When seen edgewise, the hem-like margin of this seed is less prominent then in either of the preceding three noticed above. Found almost everywhere in annual crops. Introduced from tropical America.

KNOTWEED FAMILY. ILLECEBRACEAE.

=Knawel.= _Scleranthus annuus_ L. As the seed is single for each flower, it is unnecessary for the ovary to open; the small, hardened, ten-angled calyx with its five thick lobes aid in protecting and distributing the seed within. The seed is seldom seen. Calyx straw colored, obovoid, 2 mm. long besides the five spreading, membranaceous lobes, which are nearly as long. A low spreading plant, resembling some kinds of chickweed.

AIZOACEAE.

=Carpet-Weed.= _Mollugo verticillata_ L. Seeds orange-red, shining, flattened, kidney-shaped or ovoid, .4-.6 mm. long, concave on the thinner edge from which protrudes a nipple-like point, a low central ridge passing over the rounded edge. Native of warmer America. Needing sand.

PINK FAMILY. CARYOPHYLLACEAE.

=Cockle.= _Agrostemma Githago_ L. Flowers rose-colored; pod erect, ovoid, about 16 mm. long; seeds dark brown to black, wedge-shaped-triangular, appearing as though the two extremities were bent together; surface covered with curved rows of conspicuous teeth, one side 3-3.5 mm. long. Introduced from Europe. In no sense a weed except in wheat fields.

=Thyme-leaved Sandwort.= _Arenaria serpyllifolia_ L. Flowers white; seeds reddish brown to lead color, slightly flattened, circular to short-kidney-shaped. Each side covered with 4-5 curved rows of smooth, oval tubercles, giving the appearance of having two extremities bent together, about 5 mm. in diameter. Naturalized from Europe, delighting in light, poor soil. When well grown it becomes a tumbleweed.

=Larger Mouse-ear Chickweed.= _Cerastium vulgatum_ L. Flowers white; pods cylindrical; seeds light-reddish yellow to dark reddish brown; slightly flattened, 4-sided, 2 of them straight, converging, one rounded, the other narrow and notched. Some of them ovoid, others nearly circular, covered with a few irregularly curved rows of tubercles, .4-.8 mm. in diameter. In large part introduced from Europe, though a native of this continent.

=Bouncing Bet. Soapwort.= _Saponaria officinalis_ L. Flowers white; seeds dark lead-color, flattened, short-kidney-shaped to circular with notch on one side, 2 mm. across, more or less, with 6-7 curved rows of short, shiny tubercles. Naturalized from Europe, delighting in sandy soil.