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Achilleo mitlefotium. Yarrow, nose-bleed, (p.) English agricultural wr ters speak of it as a plant of some value in their pastures; but it is generally regarded in this country as a mere weed. Certainly it is far inferior to our usual pasture plants, and our cattle are rarely, if ever, observed to eat it.
Leuca' themum vulgare. Ox-eye, daisy, white weed, (p.) This intruder from Europe has obtained almost exclusive possession of many fields is eastern Pennsylvania, and the prospect of getting rid of it appears to be nearly hope leas. Its propagation and diffusion are so rapid and irre sistible that one negligent sloven may b come the source of a grievous annoyance to a whole neighborhood. The culthation of hoed crops for a few years will rid a field of this obstruction to useful vegetation. The Corn Mari gold, Chrysanthemum tegetum, a kindred plant, which is said to be such a pest to the agriculture of the Old World, happily does not appear to have found its way as yet to the United States.
Erechthites hieracifolia. Fire Weed, (a.) This coarse native weed is remarkable for its prevalence in newly cleared grounds, especially in and around the spots where brush-wood has been burnt; hi.nce its common name of fire-weed.
&fleet° vulgaris. Common Groundsel, ragwort, (a.) A homely worthless little herb, which Prof. De Caudolle remarks migrates almost everywhere with European meu. It is naturalized about the seaports of the northein States, and has lately appearedin eastern Pennsylvania.
- Centaurea cyanus. Ragged Robin, blue bonnets of the i Scotch, (a.) This European plant is often seen in our gardens, and in some places is gradually straggling into cultivated fields. As it is considered a troublesome weed among the grain crops of the Old World, it should be watched here, so as to prevent the blue bonnets from com ing over the border.
Cirsium lanceotaturn. Common Thistle, (b.. This foreigner, which delights in a rich soil, is abundantly naturalized in Pennsylvania and in the northern States generally. It is a very objectionable weed on our farms, requiring constant vigilance and attention to exclude or keep it in subjection. If permitted to mature its fruit, the expanded pappue may be seen by thousands floating its 'skeane through the air, and disseminating the obnoxious 'intruder far and wide. The common thistle, having no creeping roots, is not so obstinate in resisting extirpation as some other varieties. It is easier destroyed if the roots are cut with sufficient care before its flower ng see son.
Cirsium horridul um. Yellow Thistle, (b.) This rugged, repulsive species looks like a stranger here, being hitherto chiefly restricted to the sandy seacoast of New Jersey. It is certainly desirable that it should continue to he a . stranger to every agricultural district.
Cirstum arvense. Canada Thistle, (p.) This is perhaps the most pernicious and detestable weed that has as yet invaded the farms of our country. Though miscalled Canada thistle, it is believed to be indigenous to Europe, and has probably acquired that name by reaching us via Canada. The rhizome or subterranean stem (which is perennial and very tenacious of life) lies rather below the usual depth of furrows, and hence is not destroyed by common . plowing. The rhizome ramifies and extends itself horizontally in all directions, sending up branches to the surface, where radical leaves are developed the first year, and aerial stems the second year. The plant, that is, the aerial portion, appears to die at the end of the second summer like a biennial, but it only dies down to the rhizome or subterranean stem. The numerous branches sent up from perennial rhizome soon furnish prickly radical leaves, which cover the ground so as to prevent cattle from feeding where those leaves are. Nothing short of destroying the perennial portion of the plant will rid the ground of this pest; anti this has been accom plished by a few years of continued culture, (or annual cropping of other plants which require frequent plowing or dressing with the hoe,) so as to prevent the develop ment of radical leaves, and thus deprive the rhizome of all connection or communication with the atmosphere. We have a few other thistles which are all worthless weeds; but not being so obnoxious as the preceding, it is not deemed necessary to notice them further here. Lappa major. Burdock, (b.) Everybody knows this coarse, homely foreign weed; one of the earliest and surest evidences of slovenly negligence about a farm yard. Cichoriurn intybus. Wild Succory, chiccory, (p.) This foreigner is becoming extensively naturalized. Some European agriculturists recommend it as a valnable forage plant, and cattle seem fond of it; though it is believed to impart a bad taste to the milk of cows which feed upon it. In Europe the roasted 'root is used as a substitute for coffee. In this country the plant is gen erally regarded as an otectionable weed.