Chapter I: Part 1

BULLETIN 260 MARCH, 1910

MICHIGAN

STATE AGRICULTURAL COLLEGE

EXPERIMENT STATION

DIVISION OF BOTANY

SEEDS OF MICHIGAN WEEDS

BY
W. J. BEAL

EAST LANSING, MICHIGAN
1910

_The Bulletins of this Station are sent free to all newspapers in the State and to such individuals interested in farming as may request them. Address all applications to the Director, East Lansing, Michigan._

MICHIGAN AGRICULTURAL EXPERIMENT STATION

Postoffice and Telegraph address, East Lansing, Mich.
Railroad and Express address, Lansing, Mich.

A DEPARTMENT OF THE STATE AGRICULTURAL COLLEGE, AND, WITH IT, CONTROLLED BY THE

INCORPORATED

STATE BOARD OF AGRICULTURE

HON. ROBERT D. GRAHAM, Grand Rapids,
Chairman of the Board, Term expires 1914
HON. WM. J. OBERDORFFER, Stephenson, Term expires 1912
HON. Wm. L. CARPENTER, Detroit, Term expires 1912
HON. ALFRED J. DOHERTY, Clare, Term expires 1914
HON. I. R. WATERBURY, Detroit, Term expires 1916
HON. WILLIAM H. WALLACE, Bay Port, Term expires 1916
HON. FRED M. WARNER, Governor of the State, _Ex officio_
JONATHAN L. SNYDER, A. M., LL. D.,
President of the College, _Ex officio_
HON. L. L. WRIGHT, Ironwood, _Ex officio_
ADDISON M. BROWN, A. B., Secretary.

STATION COUNCIL

JONATHAN L. SNYDER, A. M., LL. D., Pres., _Ex officio_
ROBERT S. SHAW, B. S. A., Director
CHARLES E. MARSHALL, Ph. D., Scientific and Vice
Director and Bacteriologist
R. H. PETTIT, B. S. A., Entomologist
A. J. PATTEN, B. S., Chemist
H. J. EUSTACE, B. S., Horticulturist
J. A. JEFFERY, B. S. A., Soil Physicist
W. J. BEAL, Ph. D., Botanist
V. M. SHOESMITH, B. S., Farm Crops
ADDISON M. BROWN, A. B., Secretary and Treasurer

ADVISORY AND ASSISTANT STAFF.

C. P. HALLIGAN, B. S., Asst. Horticulturist
O. RAHN, Ph. D., Asst. Bacteriologist
A. C. ANDERSON, B. S., Asst. Dairy Husbandryman
J. B. DANDENO, Ph. D., Assist. Botanist
G. D. SHAFER, Ph. D., Research Asst. in Entomology
M. A. YOTHERS, B. S., Asst. in Entomology
W. GILTNER, D. V. M. M. S., Research Asst. in Bacteriology
C. W. BROWN, B. S., Research Asst. in Bacteriology
F. A. SPRAGG, M. S., Research Asst. in Crops (Plant Breeding)
C. S. ROBINSON, M. S. Research Asst. in Chemistry
MISS Z. NORTHROP, B. S., Asst. in Bacteriology
MISS L. M. SMITH, Ph. B., Asst. in Bacteriology
O. B. WINTER, A. B., Asst. in Chemistry
MRS. L. E. LANDON, Librarian

SUB-STATIONS.

Chatham, Alger County, 160 acres deeded--Leo M. Geismar in charge.
Grayling, Crawford County, 80 acres deeded.
South Haven, Van Buren County, 10 acres rented; 5 acres
deeded--Frank A. Wilkin in charge.

The designer of this bulletin first had in mind something of the sort for the use of his students, not only the undergraduates, but others living on farms, or teaching in Michigan and elsewhere. Whoever grows seeds to sell, or buys seeds to sow, should be benefited by consulting the illustrations which are unsurpassed for accuracy by anything in this country. They were all made by Mr. F. H. Hillman. A hand lens costing from twenty cents to a dollar is almost indispensable in examining our seeds. The brief descriptions are necessarily made by using definite scientific terms, which are explained in a glossary at the close of the work. A few weeds are not illustrated, for the reason that the plants have ceased to produce seeds, such as the horse radish, and some of them are not conspicuously bad. Not far from half the illustrations are made from small seed-like fruits, likely to be mistaken for seeds, such as are produced by dandelions, burdocks, narrow-leaved dock, all grasses. Cuts of seeds of several clovers are inserted that students may learn to distinguished them from weeds too often mixed with them.

No apology is offered for making use of the decimal scale instead of the cumbersome antiquated English scale, which fortunately is gradually growing out of use. In the back part of the bulletin are duplicate copies of the decimal scale that any one can cut out and use for measuring.

For copies of the following figures some time ago prepared by Mr. Hillman, we are indebted to the authorities of the Agricultural College, of Reno, Nevada: 7, 11, 12, 16, 17, 23, 24, 31, 32, 34, 35, 36, 37, 39, 40, 41, 42, 44, 46, 55, 56, 58, 63, 68, 69, 71, 74, 75, 84, 86, 87, 91, 92, 95, 97, 98, 99, 108, 110, 116, 125, 130, 135, 138, 140, 144, 146, 152, 153, 158, 159, 172, 173, 174, 175, 178, 179, 181, 182, 185, 187, 189, 190, 191, 199, 203, 205, 212, 214, 215.

"A weed is any useless or troublesome plant."
"A plant out of place or growing where it is not wanted."
"Tobacco."
"A plant whose virtues have not yet been discovered."--Emerson.

Weeds everywhere; they thrive in the cornfield, they choke wheat in the field, they annoy the gardner, they thrive in the meadow, they spring up by the roadside, they encroach on the swamp, they damage the fleeces of sheep. The rapid increase in the number and variety of weeds should cause alarm.

DISADVANTAGES OF WEEDS.

1. They rob cultivated plants of nutriment.

2. They injure crops by crowding and shading.

3. They retard the work of harvesting grain by increasing the draft and by extra wear of machinery. (Bindweed, thistles, red root.)

4. They retard the drying of grain and hay.

5. They increase the labor of threshing, and make cleaning of seed difficult.

6. They damage the quality of flour, sometimes making it nearly worthless. (Allium vineale L.)

7. Most of them are of little value as food for domestic animals.

8. Some weeds injure stock by means of barbed awns. (Squirrel tail grass, wild oats, porcupine grass.)

9. Some of them injure wool and disfigure the tails of cattle, the manes and tails of horses. (Burdock, cocklebur, houndstongue.)

10. A few make "Hair balls" in the stomachs of horses. (Rabbit-foot clover, crimson clover.)

11. Some injure the quality of dairy products. (Leeks, wild onions.)

12. Penny cress, and probably others, when eaten by animals, injure the taste of meat.

13. Poison hemlock, spotted cowbane and Jamestown weed are very poisonous.

14. Many weeds interfere with a rotation of crops.

15. All weeds damage the appearance of a farm and render it less valuable. (Quack-grass, Canada thistle, plantains.)

SOME SMALL BENEFITS.

1. They are of some use in the world to induce more frequent and more thorough cultivation, which benefits crops.

2. The new arrival of a weed of first rank stimulates watchfulness. (Russian thistle.)

3. In occupying the soil after a crop has been removed they prevent the loss of fertility by shading the ground.

4. Weeds plowed under add some humus and fertility to the soil, though in a very much less degree than clover or cow peas.

5. Some of them furnish food for birds in winter.

WHAT ENABLES A PLANT TO BECOME A WEED.

1. Sometimes by producing an enormous number of weeds. (A large plant of purslane, 1,250,000 seeds; a patch of daisy fleabane, 3,000 to a square inch.)

2. In other cases by the great vitality of their seeds. Shepherd's purse, mustard, purslane, pigeon-grass, pigweeds, pepper-grass, May weed, evening primrose, smart weed, narrow-leaved dock, two chick-weeds survive when buried in the soil thirty years at least, as I have found by actual test.

3. In each prickly fruit of a cocklebur there are two seeds, only one of which grows the first year, the other surviving to grow the second year.

4. Some are very succulent, and ripen seeds even when pulled. (Purslane.)

5. Often by ripening and scattering seeds before the cultivated crop is mature. (Red root, fleabane.)

6. Sometimes by ripening seeds at the time of harvesting a crop, when all are harvested together. (Chess, cockle.)

7. Some seeds are difficult to separate from seeds of the crop cultivated. (Sorrel, mustard, narrow-leaved plantain in seeds of red clover and alfalfa.)

8. Some are very small and escape notice. (Mullein, fleabane.)

9. Some plants go to seed long before suspected, as no showy flowers announce the time of bloom. (Pigweeds.)

10. In a few cases the plants break loose from the soil when mature and become tumble-weeds. (Some pigweeds, Russian thistle.)

11. Some seeds and seed-like fruits are furnished each with a balloon, or a sail, or with grappling hooks. (Dandelion, sticktights, burdock.)

12. Some remain with the dead plant long into winter, and when torn off by the wind or by birds, drift for long distances on the snow, often from one farm to another. (Pigweeds.)

13. Some have creeping root-stocks or tubers. (Quack-grass, nut-grass.)

14. Some defend themselves with forks and bayonets. (Thistles.)

15. Most of them are disagreeable in taste or odor, so that domestic animals leave them to occupy the ground and multiply. (Jamestown weed, stink grass, milk weed.)

16. Plants with stout roots are sometimes passed over by the harrow or cultivator.

HOW ARE WEEDS INTRODUCED AND HOW ARE THEY SPREAD?

1. By live stock, carried in the hair or fleece or carried by the feet; in some instances passing alive with the excrement.

2. By unground feed-stuff purchased.

3. By adhering to the insides of sacks where they were placed with grain.

4. In barnyard manure drawn from town.

5. In the packing of trees, crockery, baled hay and straw.

6. By wagons, sleighs, threshing machines.

7. Sometimes by plows, cultivators and harrows.

8. By railway trains passing through or near a farm.

9. By ballast of boats at wharves.

10. By wool-waste at factories.

11. By birds, squirrels, and mice.

12. By water of brooks, rivers, by washing rains and by irrigating ditches.

13. By the wind aided by little wings or down, or by drifting on the snow.

14. By dropping seeds to the ground from extending branches and repeating the process.

15. By creeping root-stocks, as June grass, quack-grass and toad-flax.

16. By piercing potatoes, carrots, etc., quack-grass, June grass, Bermuda grass are sometimes carried to other fields or farms where the tubers and roots are planted.

17. A farmer buys clover seeds or grass seeds that were grown in some state that never before grew seeds that went onto his farm and thus he may get some new weeds. Seeds of alfalfa or some other crop bring new kinds of weeds, especially those of dodder. As every kind of weed goes onto a farm to stay there it follows that as a country becomes older the greater the number of kinds of weeds. As a rule each farm is annually getting more sorts of weeds, and as each farmer is cultivating weeds, they are more freely distributed in every field and along every roadside and by exchanging they are carried to neighboring and distant farms.

A great many farmers buy and sow whatever the merchant offers them under the name mentioned. For example, the college has a sample of something called clover seed, sold by a dealer in this state. It contains about 40 per cent of narrow-leaved plantain.

WHERE CERTAIN WEEDS ARE TROUBLESOME.

To begin with, years and years ago no new farm in the wilderness of Michigan contained more than twenty to thirty-five kinds of weeds, as there were not more than thirty-five sorts in the entire state, while at present there are not far from 250 kinds. A large majority of weeds hail from older countries, more especially from Europe.

There are a few weeds, like Canada thistle and quack-grass, that may infest any crop of farm or garden, but in most cases, whether to call a weed very bad depends on the nature of the crop grown, the size of the weed-seeds and their time of ripening.

Some weeds have a very wide distribution, thriving all around the world in temperate climates, while others are more limited in range; some thrive only in dry, thin, sandy soil and others in wet soils. To some extent the presence of a few weed-seeds is almost as objectionable when once on the farm, as though there were more, because these few may thrive and seed freely.

In many respects the lists of weeds for New Jersey is different from the list in Michigan, while half the weeds of Nevada or Oregon are not known in our state.

Chess, cockle, red root and rye are liable to be troublesome in fields of winter wheat, because the seeds are more or less difficult to separate from this grain and for the reason that they require a portion of two years to come to maturity.

Meadows and pastures, especially where the land is not fertile, abound in weeds that require two years or more to produce seeds, such as narrow-leaved dock, bitter dock, bull thistle, carrot, teasel, two kinds of mulleins, night-flowering catchfly, evening primrose, several kinds of fleabane, ox-eye daisy, orange hawkweed, two or three kinds of plantain, Canada thistle, hound's tongue, stick seed, sow thistle, horse nettle, buttercups, toad flax, silvery cinquefoil, and many more, not excluding some annuals, like crab-grass, tickle grass, pigeon grasses. As crops of corn, potatoes, beans, turnips, beets and squashes are ready to harvest at the close of one growing season they are molested more or less by pigeon grasses, several pigweeds, purslane, crab-grass, barnyard grass, tickle grass and a number of others.

In 1897 some seventy-five lots of timothy seeds were examined and the following list of twenty-four species of weeds were found. Doubtless other weeds may still be found in other lots of timothy seed. No sample was entirely free from weeds. Pepper grass was most common, next followed tumble weed and then shepherd's purse:

Amaranthus graecizans, Tumble weed.
Amaranthus retroflexus, Rough pigweed.
Anthemis Cotula, May weed.
Brassica arvensis, Charlock.
Brassica nigra, Black mustard.
Bursa Bursa-pastoris, Shepherd's purse.
Carduus arvensis, Canada thistle.
Carex straminea. A kind of sedge.
Chenopodium album, Pigweed.
Chenopodium filicifolium, Another kind of pigweed.
Lactuca Canadensis, Wild Lettuce.
Lepidium Virginicum, Wild Pepper-grass.
Onagra biennis, Evening primrose.
Panicum capillare, Hair grass, tickle grass.
Plantago lanceolata, Narrow-leaved plantain.
Plantago Rugelii, Rugel's Plantain, one of the broad-leaved plantains.
Poa compressa, Flat-stemmed poa, wire grass.
Potentilla Monspeliensis, Rough cinquefoil.
Prunella vulgaris, Self-heal.
Rumex Acetocella, Field or sheep sorrel.
Sisymbrium officinale, Hedge mustard.
Verbena angustifolia, Narrow-leaved vervain.
Verbena hastata, Blue vervain.
Verbena urticifolia, White vervain.

In examining some 130 lots of clover seeds as found in the market during 1897, thirty-two kinds of weed seeds were found. Sheep sorrel was most common, next to this yellow or bitter dock and green foxtail. Only three samples of clover seed was free from weeds, but possibly some weeds might have been seen if larger quantities had been looked over.

During the year 1908, eleven years later, 47 kinds of weed seeds were found in 122 lots of seed of red clover, a gain of nearly 50 per cent.

During three months from January 1, 1910, in examining 450 lots of seeds of grasses, clovers and alfalfas, besides large numbers of common weeds that we know, were 74 kinds not known to the writer. Of these 74 kinds, probably some will never become weeds of any account. Some of these came with alfalfa from Montana and some were importations from Europe and elsewhere.

Parasitic fungi rank as weeds; such as rusts and smuts of wheat, oats, corn; apple scab, black knot of plum, brown rot of cherry, anthracnose of beans.

SOME MEANS FOR PREVENTING THE INTRODUCTION OF WEEDS AND A FEW RULES FOR THEIR EXTERMINATION.

1. The right kind of a man, who will carefully observe and study the kinds of weeds and their habits, fighting each to the best advantage, i. e. with method.

2. See that all seeds purchased or grown at home for seed are free from seeds of weeds. Although often heard, these words are too little heeded.

3. See that threshing machines, hay racks, grain bags from other farms are well cleaned before used on the farm.

4. Cook or grind screenings and burn chaff when certain weeds are suspected.

5. Send seeds to the Agricultural College, East Lansing, for identification, unless they are known to be harmless.

6. Strive to prevent weeds from ripening seeds. This is especially important late in the season in case of all pigweeds, purslane and others where the flowers are very small and are liable to be overlooked and the seeds ripen before their presence is suspected.

7. For meadow or pasture make the soil very fertile, as most weeds will then be killed or crowded by the better grass and become of little account.

8. Modify the rotation of crops with reference to killing the weeds.

9. Make a specialty of hoed or cultivated crops.

10. Make soiling crops a prominent feature in certain fields.

11. Smother weeds with quick growing and thickly seeded crops, like red clover or rye or buckwheat.

12. Keep some crops growing on the land from early spring till late autumn,--double cropping, i. e., two cultivated crops in one year for barn and cellar instead of one for use and one of weeds.

13. Cultivate thoroughly after a crop is removed.

14. Clean up and avoid leaving any vacant or out of the way places for breeding ground.

15. Where practicable, remove fences and cultivate to the gutters of the highway.

16. Keep some sheep.

17. When once begun, continue the work thoroughly from year to year, giving no quarter to weeds. This is the easiest in the long run and the royal way.

18. Where hand labor is employed, it is far less expensive and much easier to keep weeds down by raking or hoeing once a week than by going over the ground much less frequently.

The habits of a weed determine to a great extent the best mode of fighting it. Certain remedies suggest themselves for creeping perennials, like quack grass and toad flax, while different treatment is best for narrow-leaved dock; and still a different mode of attack may be adopted for crab grass and purslane.

Weeds are annuals, as pigweeds, crab grass, purslane; biennials as bull thistle and mulleins; perennials, like quack grass, Canada thistle, ox-eye Daisy.

Will it pay? The annual cost of successfully fighting a weedy farm of 100 acres in Ontario has been found to be about $75. Good cultivation in the long run pays a greater profit than slipshod culture. It not only kills the weeds, but keeps the soil in condition for securing good crops. It conserves moisture.

Perennial plants cannot gain any if the green leaves are not allowed to appear. The nourishment stored in the root stocks underground will aid the plant to send up slender leaves and if these remain, the plants gain and recruit, but if the leaves start underground and are cut off before coming to the light, these root stocks are drawn on again to furnish food to start more leaves and thus, in time become exhausted.

SEEDS OF MICHIGAN WEEDS.

ASCOMYCETES.

=Ergot.= _Claviceps purpurea._ This is a poisonous fungus, not a seed, mentioned here because it is frequently found as an outgrowth of the grain of many grasses, such as rye, timothy, red top. To mature spores, it must pass to another stage requiring six months or more.

GRASS FAMILY. GRAMINEAE.

=Quack-Grass. Couch-Grass.= _Agropyron repens_ (L.) Beauv. Florets about 1 cm. long, 5-nerved at the short-awned apex: grain seldom produced and still less frequently found apart from the floral glume and palea, linear, about 4 mm. long, base abruptly acute, apex rounded, rounded on the back or outside, inside concave. Our worst weed. Introduced from Europe.

=Wild Oat.= _Avena fauta_ L. Freed from chaff the floral glume is firm, rough, brown, thinly hairy, about 15 mm. long, awn from near the middle 2-4 cm. long with several firm twists, abruptly bent near the middle, the true grain seldom separated from the firmer floral glume. A bad weed in Oregon and California, seldom seen in Michigan.

=Field Chess.= _Bromus arvensis_ (L.) Not often seen in this country; floral glume 6-7 mm. long bearing an awn rather longer; grain much like that of _B. secalinus_ which see. Introduced from Europe.

=Soft Chess.= _Bromus hordeaceus_ L. (_Bromus mollis_). Floral glume extending beyond the grain, 5-7 nerved, 6-9 mm. long, grain rounded on the back, shape of a shallow boat, 6.5 mm. long, palea thin with comb-like teeth on the margins. Waste places, thin meadows. Introduced from Europe.

=Smooth Brome-grass.= _Bromus racemosus_ L. Florets about 9 mm. long, awn 6-10 mm. long; longer, softer, thinner, with longer awn than found in florets of _B. secalinus_ which see. Not often seen in this country. Introduced from Europe.

=Chess Cheat.= _Bromus secalinus_ L. Florets swollen a little above the middle, the floral glume rounded on the back, obscurely 7-nerved, 6-7 mm. long, an awn 3-4 mm. long, more or less; palea covering the concave side, each edge bearing a single row of stiff hairs; glume and palea closely adhering to the grain. Introduced from Europe. A weed in wheat fields.

=Barren Brome Grass.= _Bromus sterilis_ L. Floral glume minutely roughened, adhering to the grain; 5-7 nerved; 11-15 mm. long; compressed; concave in section. Introduced from Europe, becoming common in the state.

=Sand-Bur. Bur-Grass.= _Cenchrus tribuloides_ L. Spikelets consisting of the grain and its coverings, broad oval, somewhat flattened, about 7 mm. long, thinly covered by stiff, straight, barbed, prickles, 2-5 mm. long, making a disagreeable and formidable bur, often common on sandy land. Native of this country.

=Bermuda Grass.= _Cynodon Dactylon_ L., Pers., (Capriola Dactylon (L.) Kuntze). Floral glume enclosing the grain, smooth, light colored, oval to half-oval, 1.5 to 2 mm. long, in cross section with two long sides and a short side half as long; grain light brown, obovate to oval, a small nipple at the larger end.

The plant seeds in hot countries but not in cool, temperate regions; spreading chiefly by coarse, hard rootstocks. Introduced.

=Small Crab-Grass.= _Digitaria humifusa_ Pers. _Panicum lineare_ Kroach. _Syntherisma linearis_ (Kroch.) Nash. Spikelets in the rough, before severe rubbing, ovoid or oblong, flattened, 2 mm. long, first glume minute, second and third as long as the spikelet, soft with very short hairs, one of them 3-nerved, the other 5-nerved; floret after severe rubbing, brown to black, smooth, floral glume of the rounded side curving over the edges below covering with their edges about two-thirds of the palea. Introduced from Europe; becoming troublesome on thin lawns.

=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.

=Cow-herb.= _Saponaria Vaccaria_ L. Seed dull, jet-black, slightly roughened by great numbers of minute points, nearly spherical, 2.3 mm. in diameter. An annual very troublesome in spring wheat. Introduced from Europe.

=Sleepy Catch-Fly.= _Silene antirrhina_ L. Flowers pink; seeds lead-color, slightly flattened, circular to short-kidney-shaped, each side covered with 5-6 curved rows of pointed tubercles giving the appearance of having two blunt extremities bent together, .5-.7 mm. across. Compare seeds with those of _Arenaria_ above described. When in flower, two of the upper internodes are glutinous. Only found on thin soil.

=Forked Catch-fly.= _Silene dichotoma_ Ehrh. Seeds reddish-brown, flattened, the three sides and the corners rounded, thickest at one corner narrowing to the side opposite; seed scar in the middle of the narrow side, four curved rows of tubercles on either side of the seed extending to the scar, diameter 1.3 mm., the thick edge concave, containing 6-7 rows of tubercles.

=Bladder Campion.= _Silene latifolia_ (Mill.) Britton & Randle. _Silene_ (Moench) Garcke. Flowers white; pod covered by an inflated calyx, seeds dull grayish brown, flattened, wedge-shaped, oval or 3-sided, 1-1.7 mm. across, 5-7 curved rows or tubercles on each side. Naturalized from Europe.

=Night-flowering Catch-Fly.= _Silene noctiflora_ L. Flowers white; seeds dull grayish brown, very slightly flattened, oval or short kidney-shaped, nearly 1.5 mm. across, with 8-10 curved rows of tubercles on each side. Naturalized from Europe.

=Spurry.= _Spergula arvensis_ L. Flowers white; seeds jet-black, except a narrowly winged, light-colored margin, slightly flattened, circular in outline 1-1.5 mm. across, with a slight notch on one side, surface often sprinkled with delicate, fragile, light-colored prickles. Introduced from Europe. Thriving on poor, sandy land.

=Common Chickweed.= _Stellaria media_ (L.) Cyrill. _Alsine media_ L. Flowers white; seeds reddish yellow to dark brown, somewhat flattened, nearly circular, each side covered with 5-6 curved rows of tubercles, giving the appearance of having the two extremities bent together, about 1 mm. in diameter. Introduced from Europe, thriving in cool weather in shade.

PURSLANE FAMILY. PORTULACACEAE.

=Purslane. Pussley.= _Portulaca oleracea_ L. Flowers yellow, seeds jet-black, shining, flattened, wedge-shaped, having three rounded nearly equal sides, broadly oval or almost circular, often having a curved tooth or point on one side, with 3-4 curved rows of minute tubercles. Seed .5-.8 mm. in diameter. Naturalized from the southwest. Every gardener knows how difficult it is to exterminate this weed.

CROWFOOT FAMILY. RANUNCULACEAE.

=Small-flowered Crowfoot.= _Ranunculus abortivus_ L. Achene light brown to straw colored, 0.8-1.2 mm. in diameter, oblong, 0.3 mm. thick, when seen in cross sections, surface uneven with minute wrinkles, pits and dots flattened, broad oval to circular, three-sided, bearing the remains of a short curved style. Rich, low woods, not a common weed.

=Bitter or Tall Buttercup.= _Ranunculus acris_ L. Achenes dull, dark brown, two-beaked, somewhat lens-shaped, 3-4 mm. long, one edge very slightly convex, the other prominently so, or somewhat semicircular in outline, hem-like margin, obscure. Introduced from Europe. Low land.

=Bulbous Buttercup.= _Ranunculus bulbosus_ L. Achenes dull brown, nearly circular, diameter 3-4 mm.; beak short, turned to one side, surrounded by a narrow, hem-like margin. In June, many meadows of New England and New York are yellow with great numbers of flowers. Introduced from Europe. Upland; fortunately not yet common in this state.

=Creeping Buttercup.= _Ranunculus repens_ L. Achenes plump, dull, light-brown, nearly circular, diameter 3-4 or more mm.; beak more or less hooked, hem-like margin conspicuous. This species usually seeds very sparingly, but when once introduced, it looses no time in spreading by creeping stems. Introduced from Europe. Moist land; a rapid spreader by runners.

POPPY FAMILY. PAPAVERACEAE.

=Celandine.= _Chelidonium majus_ L. Yellow sap, yellow flowers; seeds dark brown to almost black, ovoid, 1.2-1.5 mm. long, with 10-12 curved vertical rows of small square depressions on each side; projecting from one side a prominent white or cream-colored ridge, irregularly wrinkled when dry. Introduced from Europe. Persistent.

MUSTARD FAMILY. CRUCIFERAE.

=Yellow or Small Alyssum.= _Alyssum alyssoides_ L. Flowers yellow; fruit nearly circular; seeds rich yellowish brown, about 1.5 mm. long, nearly straight on one edge, flattened slightly, convex on each side or one side flat, surrounded by a thin wing. Cotyledons accumbent. Introduced from Europe.

=Yellow Rocket. Winter Cress.= _Barbarea vulgaris_ R. Br. (_Barbarea Barbarea_ L. Mac. M.) Seeds roughened, dull, light brown, irregularly flattened, broad oval, circular-oval, circular-oblong, cotyledons accumbent. Introduced from Europe.

=Hoary Alyssum.= _Berteroa incana_ (L.) D. C. Flowers white; pods oval, flattened; seeds reddish brown, circular, broad oval, or rhombic in outline, about 1.5 mm. in diameter, flat on one side showing a slight groove, the other side convex, irregular owing to pressure in the pod. Cotyledons accumbent. Introduced from Europe. A thrifty weed of the mustard family.

=Charlock.= _Brassica arvensis_ (L.) B. S. P. Pods tipped with a flattened elongated-conic, often 1-seeded beak. See also cuts of rutabaga and black mustard. Introduced from Europe. See statements last above.

=Rutabaga.= _Brassica campestris_ L. Seed dull, light or dark reddish brown, roughened by an indistinct net work of ridges, very nearly spherical, 1.4-1.8 mm. in diameter. Much cultivated, inclined to escape. Included here for comparison with other species. Introduced from Europe.

=Indian Mustard.= _Brassica juncea_ (L.) Cossos. See also cuts of turnip and black mustard. Introduced from Europe.

=Black Mustard.= _Brassica nigra_ (L.) Koch. Seeds dark brown to reddish brown, 1-1.7 mm., spherical, or broadly oblong, not flattened. The surface of well developed specimens presents a delicate but evident net work of fine ridges which appear under the lens as dark lines. The scar (hilum) is a whitish, elevated spot, at one extremity of the oblong seeds. See cuts of seeds of turnip. Introduced from Europe. A vigorous persistent weed.

=Small Fruited False-Flax.= _Camelina microcarpa_ Andrz. Flowers small, yellow; pods pear-shaped, flattened, about 6 mm. long, surrounded by a vertical ridge; seeds reddish brown, granular, usually broad-oval, about 1 mm. long, slightly flattened, the vertical ridge much less prominent than in C. sativa. When wet the seed is soon covered with mucilage. Not yet very common. Naturalized from Europe.

=False Flax.= _Camelina saliva_ (L.) Crantz. The common name is derived from the fact that it is a weed of flax fields in Europe. Flowers small, yellowish; pods pear-shaped, slightly flattened, 8-10 mm. long, surrounded by a vertical ridge. Seeds reddish yellow, granular, usually oval, 2-3 mm. long, one side flat or roundish, the other furnished with a prominent vertical or oblique ridge. Seed incumbent. When wet the seed is soon covered with mucilage. Naturalized from Europe.

=Shepherd's Purse.= _Capsella Bursa-pastoris_ (L.) Medic. _Bursa Bursa-pastoris_ (L.) Britton. Flowers small, white; pods flat, nearly triangular, about 4 mm. long. Seeds reddish yellow, granular, oblong, slightly flattened, 1 mm. or less long. Each side usually bearing two longitudinal grooves, separating the surface into three nearly equal parts, these grooves indicating the position of the parts of the embryo. When placed in water, a copious coat of transparent mucilage appears on the surface. In Nevada and Colorado a great pest in fields of Alfalfa.

=Hare's Ear.= _Conringia orientalis_ (L.) Dumort. Seeds brown, surface checked off into minute irregular pits or patches; broad oval, 2-2.5 mm. long, in section nearly circular, except two opposite slight grooves near one side. Cotyledons incumbent. Introduced, not common.

=Sand Rocket.= _Diplotaxis muralis_ (L.) DC. Flowers yellow, seeds reddish yellow or reddish brown, broad oval, somewhat flattened. Mucilaginous when wet. Introduced from Europe. A vigorous weed.

=Worm-seed or Treacle Mustard.= _Erysimum cheiranthoides_ L. Flowers yellow; seeds reddish yellow, smooth, dull, about 1.2 mm. long, ovoid or oval, more or less flattened, varying much in shape; some of them acute, rhombic or triangular, becoming mucilaginous when wet. Probably introduced from Europe. If not already in some portions of the state, we may at any time expect to find three other species of Erysimum. A vigorous and prominent weed.

=Apetalous Pepper-Grass.= _Lepidium apetalum_ Willd. Petals usually wanting, sometimes 2 and minute; pods flat, nearly circular; seeds reddish yellow, flattened, ovate, 1.5-1.8 mm. long, or more exactly, nearly straight on one side and roundish on the other. Mucilaginous when wet. Cotyledons incumbent. When well developed in open places it becomes a tumble weed. Apparently naturalized from Europe.

=Field Pepper-Grass or Cow Cress.= _Lepidium campestre_ (L.) R. Br. Petals white; pods flat, nearly circular; seeds dull, dark brown, obovoid, with base acute, more or less flattened on three sides, 2-2.5 mm. long. Mucilaginous when wet. Cotyledons incumbent. Naturalized from Europe.

=Hoary Cress.= _Lepidium Draba_ L. Seed reddish brown, surface slightly uneven, slightly flattened, oval to broad oval, 2-2.3 mm. long, usually with two slight vertical grooves on each side, incumbent. This may soon appear in Michigan.

=Golden Pepper-grass.= _Lepidium sativum_ L. Seed reddish yellow to reddish brown, oval, slightly compressed, often nearly straight on one edge, usually showing two vertical grooves on each side, 2.5 mm. long, cotyledons incumbent. This is not a grass but a plant of the mustard family; it has escaped from cultivation.

=Wild Pepper-Grass.= _Lepidium Virginicum_ L. Petals white, pods flat, nearly circular; seeds granular, dull, reddish yellow, flat, ovoid with one edge straight, the other rounded, usually with a slight wing on the broad end and on the round edge. 1.5-1.8 mm. long. Mucilaginous when wet. Cotyledons accumbent.

When mature, large plants become tumble weeds. Apparently native to this country.

=Ball Mustard.= _Neslia paniculata_ (L.) Desv. Small fruits, greenish to light yellowish-brown, globular, 2 mm. in diameter, covered with net-veined ridges; 1-2 seeded, cotyledons incumbent. Not yet known in Michigan but may arrive any time. Native of Europe.

=Tall or Tumbling Mustard.= _Sisymbrium altissimum_ L. Flowers cream-color; pods long and narrow; seeds reddish yellow, oblong, about 1.5 mm. long, the apex winged. Mucilaginous when wet. Cotyledons incumbent. Introduced from Europe. One of the worst weeds in the northwest.

=Hedge Mustard.= _Sisymbrium officinale_ (L.) Scop. Flowers yellow, seeds reddish brown or yellow, oblong, while lying on the flat side, circular in outline at the middle as viewed from the edge, straight on one side from the middle tapering to each end. 1-1.5 mm. long. Mucilaginous when wet. Cotyledons incumbent. Introduced from Europe.

=Penny Cress.= _Thlaspi arvense_ L. Flowers white; pods thin, double convex, nearly circular; seeds deep reddish brown, flat-oval or ovate, covered on each side by 12-14 curved ridges which originate and terminate at the narrow extremity. 1.5-2 mm. long. Cotyledons accumbent. When eaten by cows the milk and meat has a disagreeable taste. A bad weed, especially in the north-west. Introduced from Europe.

ORPINE FAMILY. CRASSULACEAE.

=Mossy Stonecrop.= _Sedum acre_ L. Seed light, reddish-yellow, somewhat glossy, obovate to oblong, pointed at the base, slightly anatropous, compressed, 6-7 mm. long. This mossy little plant is persistent when once established in sandy soil. Introduced from Europe.

ROSE FAMILY. ROSACEAE.

=Tall Hairy Agrimony.= _Agrimonia gryposepala_ Wahl. _Agrimonia hirsuta_ (Muhl.) Bicknell. Flowers yellow. Bur, consisting of calyx and two included fruits inside of which are two seeds; lower part of bur, top-shaped, rough, grooved, above which are numerous hooked prickles in several rows, the whole 7-10 mm. long. Native of woods in this country; seeds mottled brown, flat on one side, 2.5 by 2.5 mm. not found mixed with grass seed. Several other species are nearly as troublesome as this one. Seldom found out of the woods.