Pollard : The Genus Achillea in North America 371 



by Dr. Edward Palmer near Tulare Lake, Tulare Co., California, 

 August, 1892. The specimen includes a portion of the main stem 

 with two side branches, and the dimensions given above are those of 

 the entire plant as nearly as Dr. Palmer recollects them. I have 

 observed no other specimen of this remarkable Achillea. 



* L 



8. Achillea Pecten-Veneris sp. nov. 



Plant of slender habit, 4 dm. or more in height, simple, the 

 stem markedly sulcate, loosely pubescent or villous ; leaves 8-12 

 cm. in length, oblanceolate in general outline, regularly and finely 

 bipinnatifid or bipinnate, the segments as well as the ultimate divi- 

 sions filiform, gradually reduced toward the base of the rachis ; 

 surface of the foliage obscurely pubescent with scattered hairs, the 

 somewhat clasping base of the petiole usually villous : corymb 

 rhany-branchcd, incUncd to be flat-topped, the branches and 

 branchlcts puberulent : heads 4-5 mm. in height, the bracts of the 

 involucre stramineous, carinate, each with a dorsal greenish stripe : 

 ra)'S white, scarcely exceeding 2 nmi. in length : achenes narrowly 

 elliptical, rather more broadly margined than in other members of 

 the subgenus : style much exscrted. 



Type in the herbarium of Harvard University, collected by A. 

 Duges at Guanajuato, Mexico (no. 421). Mr. Seaton's no. 354, 

 in the Herbarium of Columbia University, collected on Mt. Orizaba 

 at an altitude of 8000 feet, is also to be referred here.* 



4 



9. Achillea Millefolium L. Sp. PI. 899. 1753. 



Plant of variable stature, usually 3-6 dm. high, sparsel}' vil- 

 lous or glabrate ; leaves of thin texture, evenly bipinnatifid, the 

 petiole with dilated clasping base ; segments not closely approxi- 

 mated, the ultimate divisions linear :. corymb generally flat-topped, 

 very compound, the branchlcts glabrate : involucral bracts pale 

 stramineous with greenish keels : rays usually small (2-3 mm.), 

 white or pink : achenes linear, scarcely margined. 



Newfoundland and Canada to P^lorida, westward to the foot- 

 hills of the Rocky Mountains. Specimens selected at random 

 from various parts of this range were found to agree perfectly with 

 European material. It should be noted here that although Lin- 

 naeus cites no figure for his type, there are numerous illustrations 

 of A. Millcfolmm among the works of older authors, all of which 

 point to the same plant. 



* Since writing the above, I have been informed by Dr. J. X. Rose tliat this spe- 

 cies is exceedingly abundant throughout Central Mexico, where he is now collecting. 



