COMPOSITAE (COMPOSITE FAMILY) 849 



generally glabrous, green; root perennial. Calcareous rocks, Nfd. to B. C., s. 

 to n. N. E., Minn., etc. (Ku.) 



:!. A. borealis Pall. Similar, 1-3 dm. high ; lower leaves 1-2-ternately 

 divided; upper linear, mostly entire; heads fewer, subracemose ; involucre 

 pilose or glabrate, brownish ; root perennial. Arctic regions, s. to the serpen- 

 tine mts. of e. Que., Keweenaw Point, Mich., Col., and Wash. (Asia.) 



* * Leaves entire or some 5-cleft. 



4. A. dracunculoides Pursh. Tall (0.6-1.5 m.), somewhat woody at base, 

 xliflhtly hoary or glabrous; leaves narrowly linear and entire or the lower 

 3-cleft ; heads small and numerous, panicled. Sandy banks and prairies, 

 Man. to 111. , Mo., westw. and southwestw. 



5. A. glauca Pall. Strict, 3-6 dm. high, somewhat woody at base, minutely 

 silky-pubescent or glabrate and glaucous ; leaves linear- to oblong-lanceolate ; 

 heads as in the preceding. Prairies, Sask. to Minn, and N. Dak. (Siber.) 



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



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

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

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

 and pubescent heads ; and A. PR6CERA Willd., with more spreading branches, 

 all the leaves finely 2-pinnatifid, and heads glabrous. 



* Branching perennials, whitened with fine and close-pressed wool ; heads small, 



in leafy panicles. 



6. A. serrata Nutt. Very leafy, 1.5-3 m. high ; leaves lanceolate or the 

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

 subcylindric, 4.3 mm. 'long or less. 111. to S. Dak.; sparingly naturalized 

 eastw. 



7. A. longifblia Nutt. Stem 0.5-1.5 m. high ; leaves linear or linear-lanceo- 

 late, entire, usually glabrate above ; heads subcylindric, canescent, 4-6 mm. long. 

 Minn, to Neb., and westw. 



8. A. ludoviciana Nutt. (WESTERN MUGWORT, WHITK SAGE.) 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 slender panicles. (Including A. 

 gnaphalodes Nutt.) Dry banks, Sask. to Mich., 111., Tex., and westw.; locally 

 naturalized eastw. Very variable. 



9. A. VULGARIS L. (COMMON MCGWORT.) Tall ; leaves mostly glabrous and 

 green above f the lower surface (and the branches) white-woolly, all pinnatifid, 

 with the divisions oft&i cut-lobed, linear-lanceolate ; heads small, in open pani- 

 cles. Waste places and roadsides, and along streams, e. Que. to Ont. and Pa. 

 (Nat. from Eu.) 



10. A. KANSXNA Britton. Low, 1-6 dm. high ; leaves finely pinnatifid into 

 linear segments; heads densely woolly, in strict close panicles. Plains and 

 foot-hills, w. Kan., Col., and N. Mex. ; adventive eastw. 



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



lucral bracts herbaceous. 



11. A. STELLERI\NA Bess. (BEACH W., DUSTT MILLER, OLD WOMAN.) 

 Stout, 3-6 dm. high, from a creeping base ; leaves obovate or spatulate, pin- 

 natifid, the lobes obtuse. Sandy sea-beaches, e. Que. to N. J., and shores of 

 Oneida L., N. Y. (Haberer) ; commonly cultivated in old gardens, and recently 

 spreading extensively to sandy soil. (Introd. from n. e. Asia.) 



* * * Less branched, biennial or annual, glabrous. 



12. A. biennis Willd. Strict, tall ; lower leaves 2-pinnately parted, the 

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

 short axillary spikes or clusters, crowded in a slender and glomerate leafy 

 panicle. Gravelly banks, O. to Tenn., Mo., and northweatw. ; now established 

 eastw. by railroads and in waste places. 



GRAY'S MANUAL 64 



