Part 4

=Upright Spotted Spurge.= _Euphorbia Preslii_ Guss. _Euphorbia nutans Lag._ Seeds lead-colored obovoid-oblong, with 4 unequal sides as seen in cross-section, pitted and transversely wrinkled, with 2-5 broken wavy ridges, a fine dark, verticle line (raphe) along one corner, 1-1.3 mm. long. Native of eastern North America. Introduced in seeds of red clover.

=Thyme-leaved Spurge.= _Euphorbia serpyllifolia_ Pers. Seed ash-colored, obovoid, four-angled or nearly square in cross-section, the surface covered with four or five more or less broken obtuse transverse ridges, a slender, dark line (raphe) extending from end to end on one corner. Dry soils, like railway tracks.

CASHEW FAMILY. ANACARDIACEAE.

=Poison Ivy.= _Rhus Toxicodendron_ L. Berry nearly white, globular, about 5 mm. in diameter, drupe kidney-shaped, concave on both edges, 3 by 4.5 mm. in diameter, 2 mm. thick. To some people very poisonous to the touch; a woody shrub.

MALLOW FAMILY. MALVACEAE.

=Indian Mallow. American Jute. Velvet Leaf.= _Abutilon Theophrasti_ Medic. _Abutilon Abutilon_ (L.) _Rusby_. Flowers yellow; seeds brown, flattened, 3.5-4 mm. long, ovoid excepting a piece cut from one side of the smaller end with 3-4 curved rows of minute slender objects on each side, the raphe extending from the pointed end to the notch on one side (half anatropous). Naturalized from northern Asia.

=Bladder Ketmia.= _Hibiscus Trionum_ L. Seed brown, the surface dotted with numerous, ragged, light-colored pimples. Think of the shape as obovoid, and then bent somewhat to the side. As now found the seed is triangular in outline with rounded corners, considerably thinned toward one corner near which is the seed scar in the midst of a depression. Each side of the triangle is about 2 mm. long. Introduced from Europe. Not yet a prominent weed in Michigan.

=Cheeses. Running Mallow.= _Malva rotundifolia_ L. Flowers white; cluster of 12-15 fruits flattened, circular with depression on each side, ovary circular, wedge-shaped, very slightly roughened, with radiating ridges; seeds light brown, nearly smooth, flattened, 1.4-1.7 mm. in diameter, wedge shaped, nearly circular with a small notch on the thin edge. Naturalized from Europe.

=Whorled Mallow.= _Malva verticillata._ L. Flowers white; cluster of 10-12 fruits flattened, circular with depression on each side, carpel circular, wedge-shaped, about three rows of irregular shallow pits on the wide edge, radiating ridges on each flat side; seeds light brown, nearly smooth, flattened, wedge-shaped, ovate or nearly circular, 1.5-1.7 mm. long, with a small notch on the thin edge. Introduced from the west.

=Prickly Sida.= _Sida spinosa_ L. Seed smooth, dull brown or reddish brown, having one side round and two sides flat or more or less concave, all edges obtuse while lying on one flat side, broadly ovoid, with one side nearly straight, scar at the larger end in the midst of a slight depression, 1.5-1.8 mm. long. Not yet common in Michigan. Introduced from the tropics.

ST. JOHN'S-WORT FAMILY. HYPERICACEAE.

=Common St. John's-wort.= _Hypericum perforatum_ L. Seed dark brown, mottled with about twenty-four vertical rows of small scars, short oblong, 1 mm. long, a little more or less, circular in cross-section, a slight point at one or both ends. Troublesome in old meadows and pastures. From Europe.

EVENING-PRIMROSE FAMILY. ONAGRACEAE.

=Small-flowered Gaura.= _Gaura parviflora_ Dougl. Achenes greenish brown, at first glance, having the appearance of barley, linear, swollen in the middle, more or less grooved or channeled, 6-8 mm. long. Introduced from the South.

=Common Evening-Primrose.= _Oenothera biennis_ L. _Onagra biennis_ (L.) Scop. Flowers yellow; seeds reddish brown or darker, surface dull, minutely ridged, very irregular in shape owing to crowding in the pod, more or less pyramidal and four or five sided, the angles acute or with a wing-like border, 1.-1.5 mm. long. Native to this country.

PARSLEY FAMILY. UMBELLIFERAE.

=Water Hemlock.= =Mosquash Root.= =Beaver Poison.= _Cicuta maculata_ L. Achenes, when young grow in couples joined by their flat sides, broadly oval, somewhat flattened, a single one-half oval, 2.7-3.2 mm long, with five corky yellowish white vertical stripes alternating with four brown oil tubes, the flat side with two wide light corky stripes including two brown oil tubes. The roots are very poisonous. Native to Michigan and elsewhere. Moist or wet lands.

=Poison Hemlock.= _Conium maculatum_ L. Flowers white, achenes growing in pairs, light brown, oval, flat on one side, five ribs extending from one end to the other, between them the surface abounds in minute vertical projections, achene about 3.5 mm. long. Difficult to identify. Introduced from Europe.

=Wild Carrot.= _Daucus Carota_ L. Flowers white; achenes light brown, striped with white, oval, flattened, bearing numerous frail spines along the edges and in two rows lengthwise of one face, tips of spines diverging, often hooked, about 3.5 mm. long not including the spines. Introduced from Europe. This is the cultivated carrot escaped from fields and gardens. A great pest in old meadows.

=Wild Parsnip.= _Pastinaca sativa_ L. Flowers yellow; achenes growing in pairs, 5-6 mm. long, with flat sides together, light brown, broad oval, much flattened, surrounded by a narrow thin ridge, 9-curved shallow ribs on one side. Introduced from Europe.

MILKWEED FAMILY. ASCLEPIADACEAE.

=Common Milkweed.= _Asclepias Syriaca_ L. Pods 8-12 cm. long, covered with soft spiny processes; seeds dull light brown, much flattened, narrowly obovate, 6.5-8 mm. long, the small end truncate, surrounded by a broad wrinkled wing-margin or hem. The concave side bears a slender vertical ridge (raphe) for two-thirds of its length; the convex side bearing fine, short ridges. Before escaping from the pods, the small end of the seed contains a cluster of spreading silky hairs (coma) 2-3 cm. long. Native of this country. Often troublesome and conspicuous in light soil, occasionally becoming small, pale, with slender branches and dying.

=Black Swallow-wort.= _Cynanchum nigrum_ (L.) Pers. _Vincetoxicum nigrum_ Moench. Smooth pods of the vine about 5 cm. long; seeds brown when dry, much flattened, concave, obovate, 6-8 mm. long, nearly surrounded by a wing margin or hem, the small end truncate. The concave side bears a slender vertical ridge (raphe) for over half its length, both sides bearing fine short ridges. Before escaping from the pods, the small end of the seed contains a cluster of spreading silky hairs. Introduced from Europe; not yet common, but it is persistent where once started.

MORNING GLORY FAMILY. CONVOLVULACEAE.

=Small Bindweed.= _Convolvulus arvensis_ L. Color of seeds dull dark brown, coarsely roughened, oval, 3-4 mm. long, one face convex, the other face sloping to the edges from a broad, central ridge, becoming mucilaginous when soaked in water. Introduced from Europe. Seldom, if ever, seeding in Michigan. On dry, poor land.

=Hedge or Great Bindweed.= _Convolvulus sepium_ L. Pod nearly globose, about 8 mm. in diameter, usually covered by the bracts and calyx; seeds dull black or dark brown, roughened, oval, about 5 mm. long, one face convex, the other face sloping to the edges from a central ridge. Native to this country. Seldom seeding in Michigan. On low land.

=Field Dodder.= _Cuscuta arvensis_ Beyrich. A pale yellow leafless parasitic vine; seeds dull, yellowish brown, minutely pitted, considerably resembling those of red clover, broad oval, ovoid or spherical, .7-1 mm. long, one side rounded the other often with two flat surfaces terminating in a ridge. Not uncommon with alfalfa.

=Flax Dodder.= _Cuscuta Epilinum_ Weihe. Stems very slender, yellow or red, a parasitic vine; seeds dull, yellowish to dark brown, minutely pitted, nearly spherical, oval, ovoid, 1-1.5 mm. long. Introduced from Europe.

=Clover Dodder.= _Cuscuta Epithymum_ Murr. Stems very slender, a parasitic vine; seeds oval to spherical, dull, pitted, color yellowish, light to dark brown, light green to purple, about 2 mm. long. Introduced from Europe. Occasionally found on red clover.

=Gronovius Dodder.= _Cuscuta Gronovii_ Willd. Seed light to dark brown, surface minutely granular, free from gloss, a few spherical, most of them indented as they dry or variously angled where they crowded against each other in the pod, 1.5-1.7 mm. in diameter. Species of dodder are difficult to distinguish one from the other. This is common on low land, where it draws nourishment from a great variety of plants, such as willows, balsams, nettles.

=Spanish Dodder.= _Cuscuta planiflora_ Tenore. Color light to dark pink, purple buff, olive green; surface well roughened, almost reticulated, in shape flattened on one side, ovoid, oval angled, indented in great variety, 0.7-1.2 mm. long.

BORAGE FAMILY. BORAGINACEAE.

=Hound's Tongue.= _Cynoglossum officinale_ L. Flowers reddish purple; ovary brown deeply 4-lobed separating into four achenes, 5-7 mm. long, flattened, broadly ovate or circular, excepting a slight extension at one end, lower side having an ovate scar, nearly half as long as the achenes, all the rest of the surface clothed with straight, stiff, cap-shaped hairs, bearded on all sides. Introduced from Europe. Very objectionable in pastures.

=Stick-Seed. Burr Seed.= _Lappula echinata_ Gilibert. _Lappula Lappula_ (L.) Karst. Flowers blue, ovary deeply 4-lobed separating into four warty achenes, each one brown, about 2.5 mm. long, slightly flattened, ovate with wedge-shaped apex; the upper side bearing a few stiff straight, diverging cap-shaped hairs, bearded on all sides; lower side destitute of hairs, bearing a straight ridge from the point to the middle of the large end. Introduced from Europe. Very objectionable in pastures.

=Wild Comfrey.= _Lappula Virginiana_ (L.) Greene. Flowers blue; ovary deeply 4-lobed separating into four brown achenes, about 3 mm. long, flattened on upper side, broadly ovate, the apex wedge-shaped, the upper side clothed with stiff straight cap-shaped hairs, bearded on all sides; lower side a low 4-sided cone, nearly smooth with a concave triangular scar. Native to rich woodlands.

=Red Root. Wheat Thief. Corn Gromwell.= _Lithospermum arvense_ L. Flowers white; ovary 4-divided separating into four hard, conical-ovoid achenes, each dull gray, erect, wrinkled, 2.5-3 mm. long, convex on the back, keeled on the inner side, base obliquely truncate, containing two minute white tubercles. A prominent weed of high rank in fields of winter wheat.

VERVAIN FAMILY. VERBENACEAE.

=Blue Vervain.= _Verbena hastata_ L. Achenes crowded, four together until mature, dull, reddish brown, flattened, oblong, 1.7-2 mm. long, bordered by a narrow margin, the outer face convex, bearing 3-5 small vertical ridges branching and uniting at the apex, forming a distinct network, the inner face sloping to the margin from a central vertical ridge; a light colored scar is seen on one side of the base. Native to this country. Not important.

=Nettle-leaved Vervain.= _Verbena urticifolia_ L. Achenes 1.6-1.8 mm. long, very closely resembling the last above mentioned. The achenes of this one are a trifle shorter and broader, more nearly oval than oblong. Native to this country. Not common in fields.

MINT FAMILY. LABIATAE.

=Dead Nettle.= _Lamium amplexicaule_ L. Achenes light brown, conspicuously marked by white spots some of which coalesce making the surface striped crosswise, obovate-oblong, pointed at the smaller end, 1.5-2 mm. long, the outer surface rounded, the inner face angled, the concave surfaces sloping to the edges from a central vertical ridge. Introduced from Europe. Thrives in cool weather.

=Motherwort.= _Leonurus Cardiaca_ L. Achenes light brown, obovoid-oblong, rounded on one side flat on the other two sides, the truncate apex hairy, 2-2.4 mm. long. Introduced from Europe. Waste places.

=White Hoarhound.= _Marubium vulgare_ L. Achenes dull, varying from light to dark brown, sometimes finely roughened by numerous minute tubercles, slightly flattened, oval or obovoid, about 2 mm. long, outer surface convex, inner face angled sloping to the edges from a central vertical ridge, edges of achenes often slightly margined, surface lightly grooved. Introduced from Europe. A weed in northern Michigan where snow protects it in winter.

=Catnip. Catmint.= _Nepeta Cataria_ L. Achenes dull, light reddish brown to nearly black, with two laterally placed cavities near the base, each filled with white spongey tissue, broadly oval, slightly flattened, 1.3-1.7 mm. long. Introduced from Europe. Scarcely a weed.

=Self-heal. Heal-all.= _Prunella vulgaris_ L. Achenes light to dark brown, slightly roughened, having a diffused luster, slightly flattened, oval or oblong, the base tapering to a small whitish, triangular appendage, outer side convex having dark verticle lines, the other face sloping to the edges from a central ridge, becoming mucilaginous when soaked in water. Native to this country.

NIGHT SHADE FAMILY. SOLANACEAE.

=Jimson Weed. Thorn-apple.= _Datura Stramonium_ L. Pods ovoid, densely prickly, about 4 cm. long; seeds black to brown, flattened, with 6-10 slight irregular elevations, the whole surface covered with minute shallow pits, short kidney shaped, i. e., one edge nearly straight or slightly notched, the remainder of the margin making about two-thirds of a circle. 3-3.5 mm. long. Most likely introduced from Asia. A coarse, poisonous weed found in waste places.

=Purple Jimson Weed. Purple Thorn-apple.= _Datura Tatula._ The color of the stems are purple, the flowers and pods nearly the same as those last above; seeds of the two scarcely if at all unlike. Naturalized from tropical America. Waste places.

=Horse Nettle.= _Solanum Carolinense_ L. Berry orange-yellow, 1.6 to 2 cm. in diameter; seeds lemon yellow, slightly double convex, obovate 2.1-2.9 mm. long, surface finely granular all over. Native of the southwest U. S. It spreads rapidly by long roots.

=Black Nightshade.= _Solanum nigrum_ L. Berry black, smooth, globose, 8-10 mm. in diameter; seeds finely granular, dull, yellowish to light brown, flattened, unsymmetrically ovate, about 1.5 mm. long. Native to this country. I have the best of authority for saying that these berries when ripe make good pies, whether the uncooked fruit is poisonous there is less proof. Of little importance.

=Beaked Nightshade.= _Solanum rostratum_ Dunal. Fruit surrounded by a persistent prickly calyx about 2 cm. long; seeds flattened, irregularly undulate or wrinkled, dark brown or black, usually ovate or circular in outline, 2-2.5 mm. in diameter, surface covered with small pits. Introduced into Michigan from the southwest. A coarse prickly weed.

FIGWORT FAMILY. SCROPHULARIACEAE.

=Butter and Eggs. Toad-Flax.= _Linaria vulgaris_ Hill. _Linaria Linaria_ (L.) Karst. Flowers yellow and orange; seeds dark brown or black, flat, circular or oval, surrounded by a broad wing-margin, the wing notched and covered by numerous fine radiating ridges, the surface of the seed roughened by numerous projecting points, seed, including its wing, 1.5-2 mm. long. Introduced from Europe. A vigorous weed in meadows, spreading by seeds and by root stocks.

=Moth Mullein.= _Verbascum Blattaria_ L. Flowers yellow; pod 6 mm. diameter; seeds light to dark brown, .5-1 mm. long, columnar, lateral surface slightly angular and 6-sided, base truncate or obliquely so and broader than the rounded apex, thus somewhat thimble-shaped, each lateral face deeply pitted in longitudinal rows, the pits in contiguous rows, alternating. Introduced from Europe. A vile weed in meadows and pastures.

=Velvet-Leaved Mullein.= _Verbascum Thapsus_ L. Flowers yellow; pod 6 mm. high; seeds cannot be distinguished with certainty by means of the ordinary lens from those of moth mullein. The pitted surface seems to predominate in _Verbascum Blattaria_, while the grooved surface seems to be more common in the seeds of V. Thapsus. Introduced from Europe. Common in thin pastures.

=Wall Speedwell.= _Veronica arvensis_ L. Pods heart-shaped; seeds dull, light yellow, flattened, oval, .7-1.1 mm. long on one side appearing as though the two ends had been brought together by bending. From Europe.

=Common Speedwell.= _Veronica officinalis_ L. Pods heart-shaped; seeds dull, pale yellow, flattened, broadly oval to broadly obovate, .8-1.2 mm. long, with a small scar near the middle of one side, from which extends a faint line (raphe) to one extremity. Appearing as though introduced.

=Purslane Speedwell.= _Veronica peregrina_ L. Pods heart-shaped; seeds dull, light reddish yellow, flattened, oval to broadly obovate .5-.8 mm. long, with a small scar a little above the middle of one side, from which extends a dark line (raphe) to one extremity. Most likely native to this country.

=Thyme-leaved Speedwell.= _Veronica serpyllifolia_ L. Pods broadly heart-shaped; seeds pale yellow, a trifle darker than those of V. officinalis, light, reddish yellow, in shape and markings much like those of V. peregrina, flattened, broadly oval to obovate .5-.7 mm. long, with a small scar near the middle on one side, from which extends a dark line (raphe) to one extremity.

Apparently native to this country.

Seeds of the Veronicas are very difficult to distinguish from one another.

PLANTAIN FAMILY. PLANTAGINACEAE.

=Sand Plantain.= _Plantago arenaria_ W. & K. Seeds dark amber brown, shining, rounded on the back like the bottom of a shallow canoe, 2.5-3 mm. long, transverse groove around the middle of the back, opposite side with a groove extending lengthwise, about as wide as the ridge on either side of it; hilum in the middle of the groove. Found at Harrisville, Mich.

=Large-bracted Plantain.= _Plantago aristata_ Michx. Seeds oval, dull, light to dark brown, 2.2-3 mm. long, shaped like a shallow, thick-walled canoe with ends rounded alike, outer face marked by a shallow, transverse groove at or near the middle, a white line marking the margin at the base on the canoe inside, two white-margined pits occupying the middle of the concave side. Introduced from the west in clover seeds, not yet common.

=Rib-Grass. Narrow-leaved Plantain.= _Plantago lanceolata_ L. Seeds shining, amber-colored to brown, oval, 2-2.5 mm. long, shaped like a shallow, thick-walled canoe with ends rounded alike, a dark scar occupying the middle of the narrow concave side, a faint, transverse groove across the convex side near the middle sometimes apparent. Often found mixed with clover seeds from which it is very difficult to separate. Introduced from Europe.

=Broad-leaved Plantain.= _Plantago major_ L. Seeds, light to dark brown or very nearly black, 1-1.5 mm. long, slightly flattened, with acute edges very variable in shape, oval, oblong, rhomboidal and trapezoid, the surface roughened by slender, colored ridges, appearing under the lens as slightly wavy lines, radiating from the scar. The clear light green color of the lower end of the leaf-stem is an easy mark to distinguish this plant from another broad-leaved plantain, _P. Rugelii_ in which the base of leaf is red. Introduced from Europe. About door yards.

=Rugel's Broad-leaved Plantain.= _Plantago Rugelii Decne._ Seeds dark brown to black, much like those of P. major, but larger, 1.5-2.5 mm. long slightly flattened, with edges acute, very variable in shape, oval oblong, rhomboidal, surface minutely roughened and dull, but wholly without ridge or lines as in P. major. Native of this country. Lower end of leaf-stalk red, and not clear green as in P. major. A vile pest in clover fields.

MADDER FAMILY.

=Blue Field Madder.= _Sherardia arvensis_ L. The parts often called seeds are in reality the half-fruits ripened, each one bearing at the apex three, white, pointed, persistent calyx lobes, the inner face showing a vertical groove, and in some of the fruits the calyx is broken off. Surface dull brown, clothed with small white hairs, obovoid, 2-2.5 mm. long. Introduced from Europe, not often found in the northern states.

TEASEL FAMILY. DIPSACACEAE.

=Wild Teasel.= _Dipsacus sylvestris_ Huds. Achene brown, minutely hairy, 4 mm. long, oblong, square in cross-section, with four vertical ribs on the angles and four on the sides. Seed suspended, anatropous, supplied with endosperm. Introduced from Europe. A weed requiring two years from seed to seeding.

COMPOSITE FAMILY. COMPOSITAE.

=Yarrow. Milfoil.= _Achillea Millefolium_ L. Flowers white; achenes white to gray, finely striate lengthwise, flattened, oblong, tapering at the lower end, straight or curved. 2-2.3 long. Most likely introduced from Europe.

=Ragweed.= _Ambrosia artemisiifolia_ L. Achenes hard, straw-colored to light brown or black, top-shaped, broadly oval, 2.5-3 mm. long, besides the beak 1.5 mm. long, the sides irregularly ridged vertically, with 5-10 short teeth at the apex. Sometimes the hard covering is removed by a clover huller, exposing the naked seed. Native of the U. S.

=Great Ragweed.= _Ambrosia trifida_ L. Achenes hard, brown, more or less mottled, top-shaped, 7-8 mm. besides the stout beak 2-3 mm. long, sides with 5 stout ridges terminating in 5 short teeth. Native to the United States. River bottoms, low land, sometimes 15 ft. high.

=Corn Camomile=. _Anthemis arvensis_ L. Achenes very variable, creamy white to light brown, oblong, wedge-shaped in outline, circular to four-angled in cross-section, more or less ribbed lengthwise, a ripple-shaped scar at the narrow end; apex truncate with a minute projection in the center, often with a narrow ridge about the margin. About 1.7 mm. long. Introduced from Europe. Seldom troublesome in Michigan.

=May-weed. Dog's-Fennel.= _Anthemis Cotula_ L. Outer flowers white; achenes straw color to light brown, obovoid (large end uppermost) to oblong, circular in outline, 1.3-1.8 mm. long, with 10 warty ribs. Introduced from Europe. Old roads and waste places.

=Great Burdock.= _Arctium Lappa._ So far as I have seen the achenes of this species, when compared with A. minus, are darker colored, rather longer, the ribs more distinct.

=Smaller Burdock.= _Arctium minus_ Beruh. Possibly only a variety of _A. Lappa_ L., but the prevailing plant in central Michigan. I see no way of distinguishing the achenes of one from the other; but it makes little difference as one burdock is as bad as another.