COMPOSITE. (COMPOSITE FAMILY.) 205 



78. ARTEMISIA, L. WORMWOOD. 



Heads few- or many-flowered, discoid ; the central flowers perfect, 5-tootlied 

 (sometimes abortive), the marginal ones pistillate, 3 toothed. Scales of the 

 involucre imbricated, mostly with scarious margins. Receptacle convex, 

 naked or villous. Aehenia obovoid. Pappus none. Aromatic herbs or 

 shrubs. Leaves alternate, piunately divided. Heads small, in pauicled spikes 

 or racemes. 



1. A. caudata, Michx. Smooth; stem slender, branching, lowest 

 leaves 2 - 3-pinnately divided, the upper ones pinnate, with the divisions fili- 

 form ; heads globular, in small racemes, forming an elongated panicle. Dry 

 open woods, West Florida, and northward. Sept. (2) Stem 2-6 high. 

 Receptacle naked. Disk flowers abortive. 



2. A. vulgaris, L. (MI-GWOKT.) Stem branch! ug; leaves white-downy 

 beneath, pinuatifid, with the lobes lanceolate ; heads downy, in sleuder ter- 

 minal spicate panicles ; flowers all perfect. Waste grounds. Introduced. 



3. A. biennis, Willd. Biennial, smooth; stem simple (l-3 high); 

 leaves 1 - 2-pimiatifid, the linear lobes sharply toothed ; heads crowded in 

 terminal and axillary spikes, which form a long narrow leafy panicle ; flowers 

 all perfect. West Tennessee. 



4. A. annua, L. Annual, glabrous; stem 2 -3 high, paniculately 

 branched; leaves bipinnately divided, the lobes incised; panicles spreading ; 

 heads nodding. Tennessee. Introduced. 



79. SOLIVA, Ruiz & Pavoii. 



Heads many-flowered, momecious ; the fertile flowers in several rows, apeta- 

 lous or nearly so; the staminate few in the centre, with a 3 -6-toothed corolla. 

 Scales of the involucre 5-10, in a single row. Receptacle flat, naked. Aehe- 

 nia compressed, witli winged or thickened margins, armed with the persistent 

 rigid style. Pappus none. Small depressed herbs, with petioled piunately 

 divided leaves, and smnll sessile or rarely pedunculate heads. 



1. S. nasturtiifolia, DC. Very low and depressed; leaves on short 

 petioles, pinuately parted ; the lobes 3-4 on each side, obtuse, entire ; heads 

 sessile ; achenia cuneiform, villous at the apex ; the callous margin tubercu- 

 late-rugose throughout. South Carolina, around Charleston. Introduced. 

 Feb. - May. 



80. ARNICA, L. 



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

 late involucre lanceolate, equal, in about two rows. Receptacle Hat, hairv. 

 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, Xutt. Hirsute; radical leaves spreading, oval or 

 obovate, obtuse, 3 -5-ribhed, serrate or entire; the others (2-3 pairs) dis- 

 tant, oblong, sessile ; heads corymbose, showy ; achenia smoothisli. Wet 

 pine barrens, Florida, and northward. April -May. Stem l-2 high, 

 simple, or with few opposite branches. 



