COMPOSITE. (COMPOSITE FAMILY.) 267 



ked. Achenia obovoid, with a small summit and no pappus. Herbs or shrubby 

 plants, bitter and aromatic, with small heads in panicled spikes or racemes ; 

 flowering in summer. Corolla yellow or purplish. (Dedicated to Artemis, the 

 Greek Diana.) 



1 . Receptacle smooth : marginal flowers pistillate and fertile : disk-flowers perfect but 

 sterile : root perennial, except in No. 4. 



1 . A. dracunculoides, Pursh. Tall (3 - 5), somewhat woody at base, 

 slightly hoary or glabrous ; leaves linear and entire or the lower 3-cleft ; heads 

 small and numerous, panicled. Sandy banks of streams, S. W. Illinois (Dr. 

 Vasey, Dr. Mead) and westward. 



2. A. borealis, Pallas. Low (3' -6' high), tufted, silky-villous or nearly 

 smooth ; lower leaves 3 - b-defl at the apex, or like the others 1 - 2-pinnately parted, 

 the lobes lanceolate or linear; heads few, hemispherical, pretty large, spiked or 

 racemed. Shore of Lake Superior, and northward. (Eu.) 



3. A. Canad&nsis, Michx. Smooth, or hoary with silky down (l-2 

 high ) ; lower leaves twice-pinnately divided, the upper 3 7-divided ; the divisions 

 linear, rather rigid ; heads rather large, in panicled racemes. Shore of all the Great 

 Lakes, &c., and northward. (Eu.) 



4. A. caudata, Michx. Smooth (2 -5 high) ; upper leaves pinnately, 

 the lower 2 -3-pinnately divided ; the divisions thread-form, diverging ; heads small, 

 the racemes in a wand-like elongated panicle ; root biennial. Sandy soil, coast of 

 New Hampshire to Virginia ; also Michigan and Illinois. 



2. Receptacle smooth : flowers all fertile, a few pistillate, the others perfect. 



* Tall (l-5) and branching perennials, whitened with fine and close-pressed wool: 



heads small, ovoid, crowded in leafy panicles. 



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

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

 or pinnatifid ; heads larger than in the next, mostly sessile in narrow panicles. 

 Dry banks, Lakes Huron and Michigan, and southwestward ; especially the 

 var. GNAPHAL6DES, which has the elongated nearly entire leaves very woolly 

 both sides. 



6. A. VULGARIS, L. (COMMON MUG WORT.) Leaves mostly glabrous and 

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

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

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



* * Less branched (l-3) biennial or annual, glabrous: heads densely clustered. 



7. A. biennis, Willd. (BIENNIAL WORMWOOD.) 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 Illinois, and northwestward ; 

 rapidly extending eastward by railroad to Buffalo, Philadelphia, &c. 



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



8. A. AesfNTHiUM, L. (COMMON WORMWOOD.) Rather shrubby (2- 

 4 high), silky-hoary ; leaves 2 - 3-pinnately parted, lobes lanceolate ; heads hemi- 

 spherical, panicled. Koadsides, sparingly escaped from gardens. (Adv. from 

 Eu.) 



