Seeds of Michigan Weeds Part 6

=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.

[Ill.u.s.tration: Fig. 68.]

=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.

[Ill.u.s.tration: Fig. 69.]

=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.

[Ill.u.s.tration: Fig. 70.]

=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 p.r.i.c.kles. Introduced from Europe. Thriving on poor, sandy land.

[Ill.u.s.tration: Fig. 71.]

=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.

[Ill.u.s.tration: Fig. 72.]

=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.

[Ill.u.s.tration: Fig. 73.]

=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.

[Ill.u.s.tration: Fig. 74.]

=Bitter or Tall b.u.t.tercup.= _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.

[Ill.u.s.tration: Fig. 75.]

=Bulbous b.u.t.tercup.= _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.

[Ill.u.s.tration: Fig. 76.]

=Creeping b.u.t.tercup.= _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.

[Ill.u.s.tration: Fig. 77.]

=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.

[Ill.u.s.tration: Fig. 78.]

=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 acc.u.mbent. Introduced from Europe.

[Ill.u.s.tration: Fig. 79.]

=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 acc.u.mbent. Introduced from Europe.

[Ill.u.s.tration: Fig. 80.]

=h.o.a.ry 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 acc.u.mbent. Introduced from Europe. A thrifty weed of the mustard family.

[Ill.u.s.tration: Fig. 81.]

=Charlock.= _Bra.s.sica 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.

[Ill.u.s.tration: Fig. 82.]

=Rutabaga.= _Bra.s.sica 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.

[Ill.u.s.tration: Fig. 83.]

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

[Ill.u.s.tration: Fig. 84.]

=Black Mustard.= _Bra.s.sica 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.

[Ill.u.s.tration: Fig. 85.]

=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.

[Ill.u.s.tration: Fig. 86.]

=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 inc.u.mbent. When wet the seed is soon covered with mucilage. Naturalized from Europe.

[Ill.u.s.tration: Fig. 87.]

=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.