290 COMPOSITE, (composite family.) 



70. TANACETUM, L. Tansy. 



Heads many-flowered, nearly discoid ; flowers all fertile, the marginal chiefly 

 pistillate and 3-5-toothed. Involucre imbricated, dry. Receptacle convex- 

 naked. Achenes angled or ribbed, with a large flat top ; pappus a short crown. 

 — Bitter and acrid strong-scented herbs (ours perennial), with 1 -3-piunately 

 dissected leaves, and corymbed heads. Flowers yellow ; in summer. (Name 

 of uncertain derivation.) 



T. vrLoXRE, L. (Common Tansy.) Stem (2-4° high) smooth; leaf- 

 lets and the wings of the petiole cut-toothed ; corymb dense ; pistillate flowers 

 terete, with oblique 3-toothed limb; pappus 5-lobed. — Var. ckispum has the 

 leaves more cut and crisped. — Escaped from gardens to roadsides ; Atlantic 

 iStates. (Nat. from Eu.) 



1. T. Huron ense, Nutt. Hairy or woolly when young, stout (1-3° 

 high) ; lobes of the leaves oblong ; heads large ( ^ - 1' wide) and usually few ; 

 pistillate flowers flattened, 3-5-cleft; pappus toothed. — St. John's River, 

 Maine ( G. L. Goodale), shores of the upper Great Lakes, and westward. 



71. ARTEMISIA, L. Wormwood. 



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

 pistillate, or sometimes all similar and perfect. Involucre imbricated, dry and 

 scarious. Receptable small and flattish, naked. Achenes obovoid, with a 

 small summit and no pappus. — Herbs or shrubby plants, bitter and aromatic, 

 with small commonly nodding heads in panicled spikes or racemes ; flowering 

 in summer. Corolla yellow or purplish. (Ancient name of the Mugwort, in 

 memory of Artemisia, wife of Mausolus.) 



§ 1. Receptacle smooth ; luarfjinal ffoirers pistillate and fertile ; disk-flowers per- 

 fect hut sterile, the style mostli/ entire; root perennial, except in n. 1. 

 * Leaves dissected. 



1. A. caud^ta, Michx. Smooth (2-5° high); upper leaves pinnately, 

 the lower 2 -3-pin nately divided ; the divisions thread f or m, A\\erg\ng; heads 

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

 coast of N. II. to Va. ; also Midi, to Minn., and southward. 



2. A. Canadensis, Michx. Smooth, or hoary with silky down (1-2° 

 high); loAver leaves twice-pinnately divided, the upper 3-7-divided, the divi- 

 sions linear, rather rigid ; heads rather large, in panicled racemes. — Northern 

 N. Eng. to the Great Lakes, Minn., and nortliAvard. (Eu.) 



* * Leaves entire or some 3-cleft. 



3. A. dracunculcides, Pursh. Tall (2-5°), 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, Minn, to 111., Mo., 

 and westward. 



4. A. glauca. Pall. Strict, 1-2° high, somewhat woody at base, minutdy 

 silky-pubescent or glabrate ; leaves linear- to oblong-lanceolate ; heads as in 

 the last. — 8ask. to Minn. (Sib.) 



5. A. filifblia, Torr. Suffruticose, finely canescent, 1-3° high; leaves 

 all filiform, the lower commonly 3-parted ; heads very small and numerous, 

 crowded in a long leafy panicle. — Central Kan. to Neb., and southwestward. 



