Pollard: The Genus Achillea in North America 369 



3. A. multiflora Hook. Fl Bor. Am. i: 318. 1834. 



Northern British Columbia, 



These two species have been generally recognized in our floras. 

 They are well characterized by the simple or merely pinnatifid 

 leaves. 



4. Achillea lanulosa Nutt. Journ. Acad. Nat. Sci. Phila. 



(1834), 7:36. 1834. 



A. tomcntosa Pursh, FI. Am. Sept. 2 : 563. * 18 14. Not L. 

 A. sctacea Schwein. in Long's 2d Exp. 2: 119. 1823. Not 



Waldst. & Kit. 



Millefoli 



1837- 



Plant v^arying greatly in stature, usually from 3-5 dm. high, 

 the whole surface densely lunate, or sometimes nearly glabrate : 

 leaves all finely bipmnatifid, the segments closely approximate, the 

 ultimate divisions minute and acicular, sometimes even spinulose : 

 corymb usually circinate, in age becoming flat-topped : involucral 

 bracts stramineous with greenish keels and brown apical margins : 

 rays usually large (4-6 mm.): achenes elliptical, rather broadly 

 margined. 



From British Columbia to the Mexican boundary, eastward to 

 South Dakota, Nebraska and Kansas ; possibly also introduced as 

 a ballast weed in the East. An immensely variable species of the 

 plains, growing naturally under a great variety of conditions and 

 in various situations. I have already referred to the difficulty at- 

 tending any satisfactory disposal of this type. There is less need 

 of additional material than of carefully tabulated field notes giving 

 full altitudinal and climatic data. 



5. Achillea Calif ornica sp. no v. 



Plant robust, inclined to branch at the summit, 6-8 dm. or 

 more high : stem somewhat sulcate, villous with long appressed 

 hairs : leaves very numerous, 6-10 cm. in length, or the basal even 

 exceeding these figures, all bipinnatifid with coarse, rather crowded 

 segments, general outline linear-lanceolate, the pinnae scarcely 

 reduced toward the sessile base ; surface of the foliage glabrate, 

 the tips of the ultimate segments harsh and spinulo.se : corymb 

 very compound, inclined to be flat-topped, the branchlets pubes- 

 cent : heads 5-6 mm. in height, the involucral bracts stramineous, 

 with greenish keels and slightly fuscous margins ; rays large and 

 conspicuous (3-5 mm.): achenes linear narrowly margined. 



