COMPOSITE. (COMPOSITE FAMILY.) 291 



2. Receptacle smooth ; /lowers all fertile, a few pistillate, the others perfect. 



Two cultivated shrubby species, from Europe, with filiformly divided leaves, 

 have occasionally escaped from gardens and become spontaneous, viz., A. AB- 

 ROTINUM, L. (the SOUTHERNWOOD), of strict habit, with leaves 1 - 2-pinnatifid 

 and pubescent heads, and A. PR6CERA, L., with more spreading branches, all 

 the leaves finely 2-pinnatifid, and heads glabrous. 



* Tall (1 - 5) and branching perennials, whitened with Jine and close-pressed 

 wool ; heads small, in leafy panicles. 



6. A. serrata, Nutt. Very leafy, 6-9 high ; leaves lanceolate or the 

 upper linear, serrate, white-tomeutose beneath, green above ; heads greenish, 

 oblong, 2" long or less. 111. to S. Dak. 



7. A. longifblia, Nutt. Stem 2-5 h?gh ; leaves linear or linear-lanceo- 

 late, entire, usually glabrate above; heads oblong, canescent, 2-3" long 

 Minn, to Neb., and westward. 



8. A. Ludoviciana, Nutt. (WESTERN MUG WORT.) Whitened woolly 

 throughout ; leaves lanceolate, the upper mostly entire, the lower usually cut- 

 lobed, toothed or pinnatifid, the upper surface sometimes glabrate and green ; 

 heads campanulate, mostly sessile in narrow panicles. Dry banks, Sask. to 

 Mich., 111., Tex., and westward. Very variable. 



A. VULGA.RIS, L. (COMMON MUG WORT.) Leaves mostly glabrous and 

 green above, beneath and the branches white-woolly, all pinnatifid, with the 

 divisions often cut-lobed, linear-lanceolate ; heads small in open panicles. 

 Waste places, near dwellings. (Adv. from Eu.) 



* * Densely white-tomentose perennial ; heads large, racemose-glomerate. 

 9 A. Stelleriana, Bess. Stout, 1 - 2 high, from a creeping base ; 

 /eaves obovate or spatulate, pinnatifid, the lobes obtuse. Sandy sea-beaches, 

 E. Mass. ; locally nat. from N. E. Asia? 



* * * Less branched (1 3), biennial or annual, glabrous. 



10. A. biennis, Willd. Strict, 1-3 high; lower leaves twice-pinnately 

 parted, the upper pinnatifid ; lobes linear, acute, in the lower leaves cut- 

 toothed ; heads in short axillary spikes or clusters, crowded in a narrow and 

 glomerate leafy panicle. Gravelly banks, Ohio to Tenn., Mo., and northwest- 

 ward ; rapidly extending eastward by railroad to Buffalo, Philadelphia, etc. 



A. INNUA, L. Tall, much branched ; leaves 2-pinnately divided, the oblong 

 segments deeply pinnatifid ; heads small, in a loose ample panicle. Ind. to 

 Kan. (Nat. from Old World.) 



3. Receptacle hairy ; flowers all fertile, the marginal ones pistillate. 



A. ABsfNTHiuM, L. (WORMWOOD.) Rather shrubby (2-3 high), silky 

 hoary; leaves 2 - 3-pinnately parted, lobes lanceolate; heads hemispherical, 

 panicled. Roadsides, escaped from gardens. (Adv. from Eu.) 



11. A. frigida, Willd. Low (6 -20' high), in tufts, slightly woody at the 

 base, white-silky ; leaves pinnately parted and 3 - 5-cleft, the divisions narrow- 

 linear ; heads globose, racemose. Dry hills and rocks, Sask. to Minn., W. 

 Tex., and westward. 



72. TU SSI LA GO, Tourn. COLTSFOOT. 



Head many-flowered ; ray-flowers in several rows, narrowly ligulate, pistil- 

 late, fertile ; disk-flowers with undivided style, sterile. Involucre nearly simple. 

 Receptacle flat. Achenes cylindrical-oblong ; pappus copious, soft and capil- 



