Part 12 (2/2)
long, s.h.i.+ning, smooth or containing a few minute oppressed bristles, apex truncate, bearing a whorl of bristles, the longest having been rubbed off. Native of this country. Compare the above description with that of Erigeron annuus. Common in waste places.
[Ill.u.s.tration: Fig. 196.]
=Daisy Fleabane.= _Erigeron ramosus_ (Walt.) B. S. P. Flowers white; achenes nearly identical with those last described, Erigeron annuus, bristles shorter, less diverging, surface bearing more minute appressed hairs when seen under a lens. Native to this country and prominent in some thin meadows.
[Ill.u.s.tration: Fig. 197.]
=Sweet Everlasting.= _Gnaphalium polycephalum_ Michx. _Gnaphalium obtusifolium_ L. Outer scales of the head thin, white, stiff; achenes yellowish white or brown, slightly flattened, smooth, oval or oblong, .5-.7 mm. long. Native to this country. Not often troublesome.
Much practice with a good lens and careful comparisons with other small achenes will be necessary in identifying such specimens as are furnished by this species.
[Ill.u.s.tration: Fig. 198.]
=Low Cudweed.= _Gnaphalium uliginosum_ L. Outer scales of the head thin, brown, more or less wooly; achenes .4-.6 mm. long, yellowish white to brown, slightly flattened, smooth, narrowly oblong .4-.6 mm. long.
Achenes narrower and rather shorter than those of G. obtusifolium.
Native to this country. Not of high rank as a weed.
[Ill.u.s.tration: Fig. 199.]
=Broad-leaved Gum Plant.= _Grindelia squarrosa_ (Pursh.) Dunal. Flowers yellow; achenes creamy white or light brown, very variable in appearance, more or less flattened, often 4-angled, straight to much curved, narrowed at the base, apex truncate, often concave with a distinct marginal rim, some of them not very unlike those of Canada thistle, some of them smooth, others finely grooved or ridged lengthwise, others somewhat wrinkled, 2.5-3 mm. long. Occasionally introduced from the west with seeds of gra.s.ses or clover. Usually not persistent in Michigan.
=Artichoke.= _Helianthus tuberosus_ L. Flowers yellow; achenes black, s.h.i.+ny more or less, slightly flattened, p.u.b.escent with very short hairs, with four obtuse angles, narrowly obovate, 6-7 mm. long, one side of the smaller end projecting beyond the other side. Native of this country; cultivated by Indians.
[Ill.u.s.tration: Fig. 200.]
=Golden Mouse or Orange-Ear Hawkweed. Devil's Paint-Brush.= _Hieracium aurantiac.u.m._ Flowers orange yellow; achenes jet black, oblong, straight or curved, apex truncate, base abruptly tapering, cylindrical, the sides bearing 10 narrow, vertical ridges. Introduced from Europe. In Eastern New York and Western Ma.s.sachusetts meadows abound in large areas of this vile weed, 1.8-2.2 mm. long.
[Ill.u.s.tration: Fig. 201.]
=Mouse-Ear Hawkweed.= _Hieracium Pilosella_ L. Flowers yellow; achenes jet black, oblong, straight or curved, apex truncate, base abruptly pointed, cylindrical or narrowly oval, the sides bearing 10 narrow vertical ridges. Introduced from Europe. The achenes very closely resemble those of the orange hawkweed. It doesn't matter much, for the habits are the same, and one is about as noxious as the other.
Introduced from Europe.
[Ill.u.s.tration: Fig. 202.]
=Elecampane.= _Inula Helenium_ L. Flowers yellow; achenes light brown, straight or curved, linear, flattened, 4-5 mm. long, 4 sided with 5-8 obscure vertical ridges on each side, apex concave, the margin bearing a circle of short stiff bristles, the remains of longer ones. Introduced from Europe. Not common.
[Ill.u.s.tration: Fig. 203.]
=Marsh Elder.= _Iva xanthiifolia_ (Fresen.) Nutt. Achenes various shades of brown to black, flattened or rhombic in section, obovoid, 1.5-2 mm.
long, longitudinally, striate with fine lines. Native to the upper peninsula of Michigan where it most likely was at one time introduced from the west. It has not been found in the lower peninsula, probably because it had no means of coming across Lake Michigan.
[Ill.u.s.tration: Fig. 204.]
=Wild Lettuce.= _Lactuca Canadensis_ L. Flowers yellow; achenes black or nearly so, flattened, oval, bearing 3 ribs, the lateral ones sometimes double, the middle one slender, surface abounding in minute transverse ridges as seen under a lens, the remains of a beak sometimes remaining.
Native of this country. Other species of Lettuce are more or less troublesome.
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