COMPOSITE. (COMPOSITE FAMILY.) 227 



1. T. vulgare, L. (Common Tansy. J Stem erect, smooth; leaves 

 twice-pinnately parted, the leaflets and the margined petiole cut-toothed ; cor- 

 ymb dense; pistillate flowers terete ; pappus 5-lobed. — Var. CRfSPUM has the 

 leaves more cut and crisped, ty. — Escaped from gardens. (Adv. from Eu.) 



2. T. Huronense, Nutt. Hairy or woolly when young, stout (l°-. - > ,:> 

 high); leaves 2-3-pinnately dissected, the lobes oblong; heads large (^'-§ 

 wide) and usually few ; pistillate flowers flattened, 3 - 5-eleft ; pappus toothed. 

 4— Shores of L. Huron, St. John's River, Maine, and northwestward. 



57. ARTEMISIA, L. Wormwood. 



Heads discoid, few - many-flowered ; tha flowers all tubular, the marginal 

 ones pistillate, or sometimes all similar and perfect. Scales of the involucre 

 imbricated, with dry and scarious margins. Receptacle small and flattish, na- 

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

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

 Corolla yellow or purplish. (Dedicated to Artemis, the Greek Diana.) 



§ 1. Receptach smooth: marginal flowers pistillate and fertile: disk-flowers sterile. 



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

 smooth ; lower hares 3 - 5-cleft 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.) 



2. A. Canadensis, Michx. (Canada Wormwood.) Smooth, or 

 hoary with silky down (l°-2° high) ; lower leaves twiee-phmatcly divided, the 

 upper 3-7-divided; the divisions linear, rather rigid; heads rather large in pani- 

 eled racemes. \[— Shore of all the Great Lakes, and northward. (Eu.) 



3. A. caudata, Michx. (Slender Wormwood.) Smooth (2°-f>° 

 high); upper leaves pinnately, the lower 2 -8-pinnately divided; the divisions 

 threadworm, spreading ; heads small, the racemes in a imnd-like elongated panicle. — 

 Sandy soil, coast of New Hampshire to New Jersey; and in Illinois. 



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



4. A. Ludoviciana, Nutt. (Western Mugwort.) Whitened-ivooU 

 ly throughout, branched (l°-5° high) ; leaves lanceolate, the lower mostly cut- 

 toothed or piunatifid, the upper mostly entire, the upper surface often becoming 

 naked and smooth with age ; heads ovoid, mostly sessile, disposed mi narrow 

 leafy panicles. 1J.— Dry banks, Lakes Huron and Michigan, and westward; 

 especially the var. gnaphal6des, which has the elongated nearly entire leaves 

 very woolly both sides. 



5. A. vulgXris, L. (Common Mugwort.) Branches and lower sur- 

 face of the leaves whitish-woolly ; stem-leaves pimiatifld, with the lobes variously cut 

 or entire, linear-lanceolate ; heads ovoid, in open leafy panicles. U — Waste places, 

 near dwellings. (Adv. from Eu.) 



6. A. biennis, Willd. (Biennial Wormwood.) Smooth, simple (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, winch are 



