402 COMPOSIT.E. Cirsium. 



margins. Flowers pale rose-color. Nutt. — Not improbably our C. undula- 

 tum, var. /3. 



172. CARDUUS. Tourn. ; Linn. (excl. spec); Gcertn.fr. t. 162; DC. I. e. 

 Bristles of the pappus scabrous (not plumose) : otherwise as in Cirsium. 



§ Bristles of the pappus few and slender — Leptoch^ta, JSutt. 



\. C. occidentalis (Nutt.): perennial, dwarf; leaves deeply pinnatifid, nearly 

 smooth above, canescently lomentose beneath ; the segments somewhat pal- 

 mate; the ultimate lobes lanceolate, tipped with short spines, spinulose-serru- 

 laie- scales of the subglobose arachnnid-tomentose involucre lanceolate, erect, 

 term'inating in straight spines; the innermost scarious, spineless, acuminate. 

 Nutt. in trans. Amer. phil. soc. («. ser.) 7. /;. 418. 



St. Barbara, California, Nutlall. — Stem tomentose, 6-12 inches high- 

 Leaves 4-5 inches long, about an inch wide, with a lanceolate outline ; the 

 cauline clasping. Heads 2-3, subsessile, pale purple. Plant with the habit 

 of Cirsium discolor, Nutt.— We. have not seen this plant, the only one of the 

 genus known to inhabit this continent. May it not be some species of South- 

 ern Europe, introduced into California? 



C. pedinatus (Linn, mant.), a plant of uncertain origin, said to have been raised 

 from seeds received from Pennsylvania, is doubtless not a native of this country, and 

 is probably correctly referred by Sprengel to Carduus defloratus. 



173. ONOPORDON. VailL; Linn.; Gcertn.fr. 1. 161; Schhihrjiandb. t. 230. 



Heads many-flowered ; the flowers perfect. Scales of the ovate-globose 

 involucre imbricated, coriaceous, tipped with a lanceolate spinescent appen- 

 dage. Receptacle fleshy, deeply alveolate; the alveoli membranaceous, 

 sinuate-toothed. Tubeof the corolla incrassated atthe summit. Antherswith 

 a linear-subulate appendage, and with short tails: filaments nearly glabrous. 

 Branches of the style concreted nearly to the apex. Achenia obovoid-com- 

 pressed, 4-angled, rugose transversely. Bristles of the pappus numerous, 

 filiform, barbellulate, united atthe base into a corneous ring. — Coarse branch- 

 ino^ herbs; the stems winged by the decurrent base of the lobed or toothed 

 leaves ; the lobes and teeth spinescent. Corolla purple, rarely varying to 

 white. 



1. O. acanthium (Linn.) : stem erect, branching, somewhat woolly ; leaves 

 decurrent, sinuate, spinose-toothed, tomentose on both sides ; scales of the 

 involucre linear-subulate ; the exterior spreading, woolly at the base. DC. 

 —Engl. hot. t. 977 ; Bigel.fl. Bost.ed. 2. p. 293 ; DC. prodr. 6. p. 618. 



Waste grounds and dry pastures; introduced from Europe, and natural- 

 ized in the New England States ! July-Aug.— (D A tall cottony plant, 

 called Cotton Thistle. 



174. LAPPA. Tourn. inst. t. 156 ; Juss. ; Lam. ill. t. 665 ; DC. 



Heads many-flowered ; the flowers all perfect and similar. Involucre 

 globose ; the imbricated scales coriaceous and appressed at the base, then 



