COMPOSITAE 337 



2. Matricaria matricarioides (Less.) Porter. Rayi,ESS Camomii,E. 

 (Man. p. ioi6; I. F./ S99J-) In waste places and on ballast, Mont, to 

 Mo., Me. and Mass. Adv. from the Pacific coast.— Pennsylvania : PHlt- 

 ADEI<PHIA, Pt. Breeze. 



42. TANACBTUM L. 



1. Tanacetum vulgare L. Tansy. (Man. p. ioi6 ; I. V. /. 3gcp6.) 

 Along roadsides, mostly escaped, N. S. and Ont. to S. Dak., south to N. 

 C, Mo. and Kaus. Nat. from Eu. — Pennsylvania: Monror ; North- 

 ampton ; Bucks ; Dei<aware ; Chester ; Lancaster ; Dauphin ; 

 PERRY ; Frankwn ; Lycoming ; Tioga ; Ai^legheny. 



43. ARTEMISIA L. 



Heads with the central flowers perfect but not fruit-producing. 

 Leaves glabrous or nearly so : involucres about 2 mm. broad. 



\. A. caudaia. 

 Leaves silky-pubescent : involucres about 4 mm. broad. 2. A. Canadensis. 

 Heads with the central flowers perfect and fruit-producing. 

 Receptacle markedly villous. 3. A. Absinlhium. 



Receptacle glabrous or essentially so. 

 Leaves glabrous, or if pubescent, green, not tomentose. 

 Involucres about 4 mm. broad : perennial plant. 4. A. Abrolanum. 



Involucres about 2 mm. broad : annual plants. 



Heads scattered : involucre about i mm. high. 5. A. annua. 

 Heads crowded: involucre about 2mm. high. 6. A. biennis. 

 Leaves densely white-canescent or tomentose, at least beneath. 

 Involucres fully 3 mm. high : leaves green above ; 



blades pinnatifid or pinnately parted. 7. A . vulgaris. 



Involucres less than 2 mm. high : leaves pale on both 

 sides ; blades finely dissected. 8. A. Pontica. 



1. Artemisia caudata Michx. Tai<i, or WitD Wormwood. (Man. 

 p. 1018 ; I. F. f. S998.) In dry sandy soil, on sea beaches, Quebec to 

 Fla., Man., Neb. and Tex. — Pennsylvania : EriE, Presque Isle. 



2. Artemisia Canadensis Michx. Canada Wormwood. (Man. p. 

 1018 ; I. F. y. 4000. ) In rocky soil, Hudson Bay to northern Me. and 

 Vt., west to Minn., Man., the Canadian Pacific coast, south to Ariz, and 

 Neb. — Pennsylvania : Erie, Presque Isle. 



3. Artemisia Absinthium L. Common Wormwood. (Man. p. 

 1019; I. F.y; 400J.) In waste places, Newf. and Hudson Bay to Mass., 

 western Ont., Mont, and N. C. Nat. or adv. from Eu. — Pennsylvania : 

 Al,l,EGHENY. 



4. Artemisia Abrotanum L. Southernwood. (Man. p. 1019; I. F. 

 f. 4006.) In waste places, Mass. to N. C, Ont. and Neb. Adv. from Eu. 

 — Pennsylvania : Ai,i,egheny. 



5. Artemisia annua L. Annuai, Wormwood. (Man. p. 1019 ; I. F. 

 f. 400^.) In waste places, Ont. to D. C, Tenn., Ark. and Kans. Adv. 



or nat. from Asia. — Pennsylvania : Northampton ; Bucks ; Dei,aware. 



6. Artemisia biennis Willd. Biennial Wormwood. (Man. p. 

 1019 ; I. F.y. 4008.) Nat. in the N. W. Terr, and the northwestern U. 



22 



