Seeds of Michigan Weeds - Part 10
Library

Part 10

[Ill.u.s.tration: Fig. 146.]

=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.

[Ill.u.s.tration: Fig. 147.]

=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.

[Ill.u.s.tration: Fig. 148.]

=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.

[Ill.u.s.tration: Fig. 149.]

=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.

[Ill.u.s.tration: Fig. 150.]

=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 dest.i.tute of hairs, bearing a straight ridge from the point to the middle of the large end. Introduced from Europe. Very objectionable in pastures.

[Ill.u.s.tration: Fig. 151.]

=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.

[Ill.u.s.tration: Fig. 152.]

=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.

[Ill.u.s.tration: Fig. 153.]

=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.

[Ill.u.s.tration: Fig. 154.]

=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. l.a.b.i.aTAE.

[Ill.u.s.tration: Fig. 155.]

=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.

[Ill.u.s.tration: Fig. 156.]

=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.

[Ill.u.s.tration: Fig. 157.]

=White h.o.a.rhound.= _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.

[Ill.u.s.tration: Fig. 158.]

=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.

[Ill.u.s.tration: Fig. 159.]

=Self-heal. Heal-all.= _Prunella vulgaris_ L. Achenes light to dark brown, slightly roughened, having a diffused l.u.s.ter, 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.

[Ill.u.s.tration: Fig. 160.]

=Jimson Weed. Thorn-apple.= _Datura Stramonium_ L. Pods ovoid, densely p.r.i.c.kly, 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 coa.r.s.e, poisonous weed found in waste places.

[Ill.u.s.tration: Fig. 161.]

=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.

[Ill.u.s.tration: Fig. 162.]

=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.

[Ill.u.s.tration: Fig. 163.]

=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.

[Ill.u.s.tration: Fig. 164.]

=Beaked Nightshade.= _Solanum rostratum_ Dunal. Fruit surrounded by a persistent p.r.i.c.kly 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 coa.r.s.e p.r.i.c.kly weed.

FIGWORT FAMILY. SCROPHULARIACEAE.

[Ill.u.s.tration: Fig. 165.]

=b.u.t.ter 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.