246 COMPOSITZ. (COMPOSITE FAMILY.) 
75. RUGELIA, 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 corymbose raceme. 
1. R. nudicaulis, 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 19 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 1? - 29 high, simple, oF 
with few opposite branches. 
Treise V. CYNAREUE. 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. GSran-TnrsrLE. 
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. CIRSIUM, Tourn THISTLE. ; 
Heads many-flowered, discoid ; the flowers all similar and perfect. Seales 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 - a 
pinnatifid and spiny leaves. Heads large, subglobose. Flowers purple F 
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