456 COMPOSITvE. Cirsium. 



§ 1. Scales of the involucre more or less unequal, all hut the innermost ter- 

 minating in subulate and spinose spreading appendages : leaves decurrent. 

 (Eriolepis, Cass.) 



1. C. lanceolatum {S>co]i.) : stem branching, somewhat hairy; leaves de- 

 current on the stem and forming a spinose lobed wing, pinnaiifid, rough and 

 bristly above, somewhat glabrous or arenose-woolly beneath ; the lobes and 

 teeth tipped with spines and with spinulose margins; involucre ovoid, nearly 

 bractless, arachnoid ; the scales linear-lanceolate, tipped with spines, the ex- 

 terior spreading; flowers purple. DC. ! prodr. 6. p. 636. — Carduus lan- 

 ceolatus, Linn.; Engl. hot. t. 107 ; Fl. Dan. t. 1173 ; Hook.! fl. Bor.-Am. 

 1. p. 302 ; Darlingt. ! fl. Cest. p. 436. Cnicus lanceolatus, Willd. ; Pursh, 

 fl,. 2. p. 606 ; Bigel. fl. Bost. ed. 2. p. 292. 



Pastures and road-sides throughout the Northern and Middle States ! in- 

 troduced from Europe. Also Newfoundland, {Hook., DC.) June-Sept. — (D 

 Common Thistle. 



§ 2. Scales of the ovoid or globose involucre either mucronale or tipped, vnth 

 a prickle ; the innermost always unarmed : filaments hairy. (Onotrophe, 

 Cass.) 



• Scales of the invohtcre closely appressed and regularly imiricated in numerous series, 

 the outermost very short, the others successively elongated, all but the innermost tipped 

 with a spreading or recurved acicular prickle {leaves not decurrent, canescently tomeTV- 

 tose beneath). 



2. C. Pitcheri: canescently tomentose throughout; stem stout, very leafy, 

 simple or sparingly branched; leaves all pinnately parted, rigid; the seg- 

 ments narrowly linear, elongated, with revolute margins, terminated with 

 small prickles, entire, or sparingly and remotely pinnately parted ; heads 

 usually several, racemose-spicate in the axils of the upper leaves ; scales of 

 the o-lobose involucre oblong-lanceolate, acuminate, with arachnoid margins, 

 appressed, tipped with a small spreading prickle ; flowers ochroleucous. — 

 Cnicus Pitcheri, Torr. in Eaton, man. ed. 5. p. 180. 



On the sand banks of Lake Superior, Lake Huron, &c. Dr. Pitcher! 

 Shore of Lake Michigan, Dr. Wright! June-July.— 2i? A foot or more 

 high. Lower leaves 6-8 inches long, with a rigid narrowly margined rachis, 

 which is naked at the base ; the segments numerous, 1-4 inches long, 1-2 

 lines wide. Heads an inch in diameter, terminal, and on very short leafy 

 branches in the axils of the upper leaves. Corolla nearly regular. Fila- 

 ments somewhat pubescent. The longer bristles of the plumose pappus ob- 

 scurely thickened at the summit. 



3. C. undulatum (Spreng.) : canescently tomentose throughout; stem low, 

 angled, often branched above; the branches leafy, bearing solitary (pretty 

 large) heads; leaves lanceolate-oblong, partly clasping, sinuate-])innatifid, 

 plicate-undulate, very white and tomentose beneath ; the lobes often incised 

 or 2-cleft, spinose ; scales of the subglobose involucre lanceolate, appressed ; 

 the exterior tipped with a small and weak spreading prickle; the inner with 

 attenuated membranous tips; flowers reddish-purple. — DC. prodr. 6. p. 651. 

 C. Douglasii, DC. prodr. 6. p. 643; Nutt.! in trans. Amer. phil. soc. 

 I. c.p. 419. Carduus undulatus, Nutt.! gen. 2. p. 130. 



(3. smaller and more slender ; leaves more spinose and deeply pinnatifid. 



Calcareous Islands of Lake Huron, and Upper Missouri, Nuttall! Hills 

 of the Missouri near Fort Pierre, Mr. Nicollet! {a. & ^.) Oregon, Douglas 

 (probably not California, as given by DeCandoUe), Nuttall! June-July.— 



