180 



WEEDS AXD USEFUL PLAJiTS. 



3-lobed, armed at base witli slender 3-parted spines ; involucre of the 

 fruit cylindric-oblong, with an inconspicuous beak. 

 Spinose Xanthium. Thorny Clot-bur. 



Stem 2-3 or 4 feet high, branched. Leaves 1-3 inches long, and one-fourth to three- 

 fourths of an inch wide, entire or with a lobe-hke tooth on each side. — the upper surface 

 pale green, pubescent on the midrib — the under surface clothed with a short cinereous 

 tomeutum, — the base narrowed to a short petiole — on each side of which is a triple or 

 3-forked spine, the branches about an inch long, very sl)§rp, yellowish or pale straw color. 

 Heads of tlowers axillary, solitary. 



Farm-yards, road-sides, &c. : Massachusetts to Georgia : introduced. Native of Eu- 

 rope. Fl. September. Fr. October. 



Obs. This execrable weed, believed to have originated in tropical 

 America, and now widely diffused through various parts of the old 

 world, is becoming naturalized in many portions of our country, — par- 

 ticularly in the Southern States. It may be frequently seen along the 

 side-walks, and waste places, in the suburbs of our northern sea-port 

 towns, — and is a vile nuisance wherever found. I have understood that 

 the authorities of one of our cities, a few years since, enacted an Ordi- 

 nance against the plant, — in which enactment it was denounced by the 

 name of the Canada Thistle ! The misnomer probably did not impair 

 the efficacy of the Ordinance : yet I cannot help thinking it would be 

 decidedly preferable that both lawgivers and farmers should avoid 

 confounding objects which are essentially distinct, — and learn to desig- 

 nate even weeds by their proper names. 



10. RUDBEC'KIA, L. Coxe-flower. 



[In honor of Olaus RudbecJc, father and son ; Sweedish botanists.] 



Heads many-flowered ; ray-Jlorets neutral. Involucral scales in about 2 

 series, leaf-like, spreading. Receptacle more or less columnar ; c^o^ short, 

 conical, not rigid. Akenes 4:-angled, smooth ; pappus a minute crown- 

 like border. Chiefly perennials ; leaves alternate ; rays yellow, generally 

 long and drooping. 



1. R. hir'ta, ^- Hirsute ; lower leaves spatulate, petiolate, upper ones 

 ovate-lanceolate, sessile ; disk conical, dark purple. 

 Rough-haired Rudbeckia. 



Perennial? Slein l>^-4feet high, rather stout, often simple or branched near the 

 base. Leaves 2 3 inches long,^the radical ones on hirsute petioles 1-2 inches in length. 

 Heads of flowers middle-sized, on long stoutish striate sulcata naked peduncles ; cTiaff of 

 the receptacle sublinear, rather acute, hairy and ciliate at the summit. 



Fields and in dry soil. July - September. 



Ohs. This is of late becoming rather common in cultivated lands, and 

 cannot fail to attract the notice of the farmer. Another species which 

 nearly resembles it, R. ful'gida, -4??., is also found in similar situations ; 

 the latter has 3-uerved leaves, and smooth chaff" to the receptacle. But 

 little is known of their character as weeds, but they have apparently an 

 encroaching disposition, and should be eradicated. .* 



