Achillea. COMPOSlTiE. 409 



1. A. Ptarmica (Linn.) : leaves glabrous, lanceolate-linear, sharply and 

 equally serrate with appressed teeth; heads loosely corymbose ; rays 8-12, 

 much longer than the disk. — Linn, sjjec. 2. p. 898; Fl. Van. I. 643; Engl, 

 bot. t. Ibl ; Pursh,fl. 2. p. 5-52. Ptarmica vulgaris, DC.j^rodr. 6. p. 23. 



Canada to New York, according to Pursh : but it has not since been met 

 with. Introduced in Danvers, Massachusetts, Dr. Nicholls ! {Mr. Oakes.) 

 Aug.-Sept. — Disk and ray white. — Sneeze-wort. 



2. A. multijlora (Hook.) : clothed with villous hairs when young ; leaves 

 elongated, linear-lanceolate, closely and sharply pinnatifid-serrate ; the teeth 

 or segments lanceolate, mucronate, serrulate, somewhat appressed ; heads 

 in dense compound corymbs ; rays 10-12, very short. — Hook. ! fl.. Bar. -Am. 

 1. p. 318. A. Ptarmica, Richards. ! appx. Frankl. journ. ed. 2. p. 33. 



Woody country of Subarctic America, as far north as Fort Franklin, 

 Richardson! Druminond! — Leaves evenly and deeply pectinate-incised. 

 Ligules roundish, scarcely exceeding the disk ; in which respect it differs 

 from all other species of this section. 



3. A. horealis (Bongard) : stem striate, villous with soft hairs ; leaves ses- 

 sile, pinnately divided ; the segments bipinnatifid ; the lobes linear, acute, 

 pubescent ; heads corymbose ; the peduncles villous-pubescent, branched ; 

 exterior scales of the involucre rather obtuse, the inner oblong ; rays obovate, 

 entire, 4-nerved. DC. — Bongard, veg. Sitcha, in mem. acad. St. Petersb. 

 I. c. p. 149. Ptarmica borealis, DC. prodr. G. p. 21. 



Sitcha, Kastahky, ex Bongard. — The heads are compared with those of 

 A. atrata. Flowers white. 



§ 2. Involucre ovoid-oblong ; rays few and short ; receptacle small : achenia 

 slightly margined. — Millefolium, Tourn. (Achillea, DC) 



4. A. Millefolium (Linn.) : cauline leaves nearly sessile, bipinnately 

 parted ; the lobes linear, 3-5-cleft, mucronate ; the rachis entire or slightly 

 toothed near the apex of the leaf; corymb compound, fastigiate ; rays 4-5, 

 obovate, white, or sometimes rose-color (var. rosea). — Linn. spec. p. 899 ; 

 Fl. Dan. t. 737 ; Engl. bot. t. IbS ; Hook. ! fl. Bor.-Am. 1. j>. 318 ; Dar- 

 lingt. ! fl: Cest. p. 489 ; DC. prodr. 6. p. 24. A. gracile & A. occidentale, 

 Raf. ! in herb. DC. — Varies from almost glabrous, with the divisions of the 

 leaves slender and loose, to densely woolly, with smaller and narrower leaves, 

 and the divisions and lobes short and very much crowded ; which is A. Mille- 

 folium y. lanata, Koch : A. tomentosa, Pursh ! fl. 2. p. 319 (Interior of 

 Oregon, Lewis !) : A. lanulosa, Nutt. ! in jour. acad. Philad. 7. p. 20 ; & 

 A. setacea, Schweinitz ! in Long's 2nd exped. 2. p. 119. 



Throughout North America, from the Arctic regions ! along the Rocky 

 Mountains! to Mexico, and from Newfoundland! to Oregon! Sitcha, and 

 California. Also, doubtless introduced from Europe into pastures, &c. Aug.- 

 Oct. — The flowers of A. tomentosa, Pursh, although yellowish in the dried 

 specimen, were probably white in the living plant. — Bitter, astringent, and 

 aromatic. — Yarrow. 



A. aspleniifolia (Vent. hort. Cels.) with rose-colored rays, is of unknown origin. 

 It is said to have been raised from seeds brought from Carolina by Bosc ; but, accord- 

 ing to De CandoUe, it had been cultivated in the gardens of Europe long before the 

 time of Bosc. 



Div. 3!». Chrtsantheme*, DC. — Receptacle naked. Heads radiate ; 

 the rays ligulate, pistillate, rarely neutral, in a single series (rarely wanting) ; '^ 

 the disk flowers perfect. 



TOL. u. — 52 



