COMPOSITAE 



155 



3. C. nlf is simnm. Sprang. Radical leaves pinnatifid, petio- 

 late, stem-leaves undivided, lance-oblong, dentate, roughish above, 

 hoary -tomentose beneath. 



Carduus altissimus. L. $ Fl. Cestr. ed. 2. p. 439. 

 TALLEST CIRSIUM. 



Perennial f Stem, 3 to 6 or 8 feet high, branching and slender above, roughish- 

 pubescent. Radical leaves 12 to 18 inches long, and 3 to 5 or 6 inches wide, den- 

 ticulate, and ciliate with spinescent bristles. Heads oblong-ovoid, about an inch in 

 diameter, with linear-lanceolate spinescent-ciliate bracts at base; involucral scales 

 of a livid color near the apex, terminating in a subulate spine. Florets purple, 

 often palish. 

 Hob. Borders of thickets; fence-rows, &c.: not common, Fl. Aug. Fr. Sept. 



* * Leaves green on both sides, or loosely lanuginom beneath ; pinnatifid. 



4. C. iiiiiticiim, MX- Stem tall, with slender paniculate rather 

 naked branches; heads subglobose; involucral scales unarmed, 

 closely appressed, viscid and cobwebby. 



Carduus muticus. Nutt. $ FL Cestr. ed. 2. p. 438. 



MUTIC, OB POINTLESS ClRSIUM. 



Perennial f Stem 3 to 5 or 6 feet high, rather slender, angular-sulcate and stri- 

 ate, pubescent; branches virgate, few-leaved. Leaves 4 to 12 inches long ; segments 

 lanceolate, spinulose. Heads half an inch to an inch in diameter ; florets purple. 

 Hob. Low grounds ; swampy thickets : frequent. Fl. Aug. Fr. Spt. 



5. C. pilmilum, Spreng. Stem low, stout; leaves partly clasp- 

 ing, with irregular undulate very prickly segments; heads few, 

 large, conspicuously bracteate ; outer involucral scales with short 

 spines; florets pale red. 



Carduus pumilus. Nutt. $ Fl. Cestr. ed. 2. p. 437. 

 DWARF CIRSIUM. 



Biennial f Plant pale greyish-green. Stem 1 to 2 feet high, thick and sparingly 

 branched, striate and hairy. Leaves 4 to 12 or 15 inches long (the radical ones 

 large), densely hairy on the midrib beneath. .Heads usually 1 to 3, roundish-ovoid, 



1 to 2 inches in diameter, with large pinnatifid spinose fcrocteatbase ; florets often 



2 inches in length, pale reddish-purple, with whitish anthers. 



Hob. Sterile old fields, and low grounds : frequent. Fl. July. Fr. Aug. 



Obs. The flowers of this species are quite fragrant, and the heads 

 rather handsome, being the largest of any of our native thistles. 



<J. C. horridulurA, MX. Stem stout; leaves partly clasping, acutely 

 lobed, very spinose with yellowish prickles ; heads few, large, with 

 a verticil of pectinately-spinose bracts at base ; involucral scales 

 scarcely spinose ; florets pale yellow. 

 Carduus spinosissimus. Fl. Cestr. ed. 2. p. 438. 

 RUGQED CIRSIUM. Yellow Thistle. 



Perennial f Stem 18 inches to 2 or 3 feet high, mostly simple, striate, lanugi - 

 nous. Leaves 4 to 10 inches long. Heads often solitary, sometimes as large as in 

 the preceding species ; bracts about as long as the involucre : involucral scales ta- 

 pering to a subulate point. 

 Hob. Fields ; Londongrove : rare. Fl. July. Fr. Aug. 



Ofa. This repulsive plant may be indigenous to the U. States, 

 but it is evidently a stranger in this County ; and our farmers would 

 do well to keep it such. 



