24 G COMPOSITE. (COMPOSITE FAMILY.) 



75. RTJGELIA, Shuttl. 



Heads many-flowered, the flowers all tubular and perfect. Scales of the cam- 

 panulate involucre lanceolate, equal, in a single row. Receptacle convex, naked. 

 Corolla 5-cleft. Style bulbous at the base, the long branches truncated at the 

 apex, and beset with rigid reflexed hairs. Achenia terete, striate. Pappus of 

 numerous rather rigid rough bristly hairs. A perennial herb, with alternate 

 undivided leaves, and large heads in a simple corvmbose raceme. 



1. R. HUd.ica.ulis, Shuttl. Minutely pubescent ; rhizoma creeping ; stem 

 simple, erect ; leaves ovate, acute at each end, denticulate ; the lowest ones large 

 (2' -4'), crowded, on long margined petioles, the others small, scattered, and 

 nearly sessile ; heads on long bracted peduncles. Smoky Mountains, Tennes- 

 see, Rugel, Buckley. Stem 1 high. 



76. ARNICA, L. 



Heads many-flowered, radiate ; the rays pistillate. Scales of the campanulate 

 involucre lanceolate, equal, in about two rows. Receptacle flat, hairy. Achenia 

 terete, narrowed downward, somewhat ribbed. Pappus a single row of rough 

 bristly hairs. Perennial herbs. Leaves opposite, undivided. Heads single or 

 corymbose. > 



1 . A. nudicaulis, Ell. Hirsute ; radical leaves spreading, oval or ob- 

 ovate, obtuse, 3-5-ribbed, serrate or entire; the others (2-3 pairs) distant, 

 oblong, sessile ; heads corymbose, showy ; achenia smoothish. Wet pine bar- 

 rens, Florida, and northward. April and May. Stem l-2 high, simple, or 

 with few opposite branches. 



TRIBE V. CYNAREJE. Heads discoid ; the flowers all tubular ; the exterior 

 ones sometimes enlarged and ray-like : style thickened at the summit ; the stigmatic 

 lines extending to the summit of the branches, without appendages. 



77. CENTAUREA, L. STAR-THISTLE. 



Heads many-flowered ; the marginal flowers mostly large and sterile. Scales 

 of the involucre imbricated. Receptacle bristly. Achenia compressed. Pappus 

 of rough bristles in one or more rows, sometimes wanting. Herbs. Leaves 

 alternate. Heads solitary. 



1. C. Calcitrapa, L. Stem diffusely branched, hairy; leaves pinnately 

 lobed ; the lobes linear, toothed ; heads sessile ; involucre spiny ; pappus none. 

 North Carolina. Naturalized. Flowers purple. 



78. CIRSITTM, Tourn. THISTLE. 



Heads many-flowered, discoid ; the flowers all similar and perfect. Scales of 

 the involucre imbricated in many rows, all but the innermost ones usually spine- 

 pointed. Receptacle bristly. Achenia oblong, compressed, smooth. Pappus of 

 numerous plumose hairs. Herbs, with alternate sessile or decurrent mostly 

 pinnatifid and spiny leaves. Heads large, subglobose. Flowers purple or 

 whitish. 



