COMPOSITE. (COMPOSITE FAMILY.) 233 



Sj with sessile alternate leaves, often pinnatifid, and prickly. Heads large, 

 terminal. Flowers reddish-purple or cream-color. (Name from KI/WTOS, a swelled 

 vein, for which the Thistle was a reputed remedy.) 



# Scales of the involucre all tipped with spreading prickles. 



1. C. LANCEOLATUM, Scop. (COMMON THISTLE.) Leaves decurrent on 

 the stem, forming prickly lobed wings, pinnatifid, rough and bristly above, 

 woolly with decidous webby hairs beneath, prickly; flowers purple, (f) Pas- 

 tures and road-sides, everywhere, at the North. (Nat. from Eu.) 



* * Si-ales of the involucre oppressed ; the inner ones not prickly : filaments hairy. 



- Leaves white-woolly beneath, and sometimes also above : outer scales of the involucre 



successively shorter, and tipped with short prickles. 



2. C. Pitcberi, Torr. & Gr. White-woolly throughout, low; stem stout, 

 very leafy ; leaves all pinnately parted into rigid narrowly linear and elongated divis' 

 ions, with re volute margins ; flowers cream-color. 1J. Sandy shores of Lakes 

 Michigan, Huron, and Superior. 



3. C. imdulatUID, Spreng. White-woolly throughout, low and stout, 

 leafy; leaves lanceolate-oblong, partly clasping, undulate-pinnatifid, with prickly 

 lobes ; flowers reddish-purple. @ Islands of L. Huron and Michigan ; 

 thence westward. July. 



4. C. discolor, Spreng. Stem grooved, hairy, branched, leafy ; leaves 

 all deeply pinnatifid, sparingly hairy and green above, whitened with close woof be- 

 neath ; the diverging lobes 2 - 3-cle/l, linear-lanceolate, prickly-pointed ; flowers pale 

 purple. (D Meadows and copses; not uncommon. Aug. Plant 3 -6 

 high : heads 1 ' or more in width. 



5. C. altissinilllll, Spreng. Stem downy, branching, leafy to the heads: 

 leaves rough ish-h airy above, whitened with close wool beneath, oblong-lanceolate, 

 sinuate-toothed, undulate-pinnatifid, or undivided, the lobes or teeth prickly, those 

 from the base pinnatifid; lobes short, ^ong or triangular ; flowers chiefly purple, 

 1J.? Fields and copses, Penn. to Ohio, Illinois, and southward. Aug. 

 Plant 3 - 10 high : leaves variable : the heads much as in the last. 



G. C. ViJ'sriiiiammi, Mkhx. Stem woolly, slender, simple or sparingly- 

 branched, the branches or long peduncles naked: leaves lanceolate, green above, 

 whitened with close wool beneath, ciliate with prickly bristles, entire or sparingly 

 sinuate-lobed, sometimes the lower deeply sinuate-pinnatifid ; outer scales of the 

 involucre scarcely prickly ; flowers purple. Woods and plains, Virginia, Ohio, 

 and southward. July. Plant 1 - 3 high ; the heads seldom more than half 

 as large as in the last. 



Var. filipeiidlllllin. Stem stouter, more leafy, corymbosely branched 

 above ; the heads on shorter peduncles ; leaves pinnatifid ; roots tuberous, en- 

 larged below. (C. filipendulum, Engelm.) Illinois and south west ward. 

 *- *- Leaves green both sides, or only with loose webby hairs underneath : scales of ihe 

 involucre scarcely prickly-pointed. 



7. C. muticum, Michx. (SWAMP THISTLE.) Stem tall (3 -8 high), 

 angled, smoothish, panicled at the summit, the branches sparingly leafy and 

 bearing single or few rather large naked heads; leaves somewhat hairy above. 



